CBS North Tower desmorona

CBS North Tower desmorona


We are searching data for your request:

Forums and discussions:
Manuals and reference books:
Data from registers:
Wait the end of the search in all databases.
Upon completion, a link will appear to access the found materials.


KELO-TV atende a maior área de exibição de qualquer estação nos Estados Unidos. Ele chama essa vasta área - que consiste em toda a Dakota do Sul, bem como partes de Iowa, Minnesota, Montana, Nebraska, Dakota do Norte e Wyoming - "KELOLAND". Ele cobre esta região com uma rede de três semissatélites de potência total, conhecidos como KELOLAND Media Group (originalmente conhecido como "TV KELO-land"de 1954 a 1991, e então como o"KELOLAND Television [rede]"daí em diante até fevereiro de 2020).

Edição de tradutores

Edição KCLO-TV

Um terceiro semi-satélite, KCLO-TV (canal 15) em Rapid City, limpa toda a programação da rede fornecida por seu pai e transmite os noticiários da KELO-TV (com inserções de clima local), mas exibe uma oferta separada de programação sindicalizada, também há inserções comerciais separadas e identificações legais de estações. Embora a KCLO-TV mantenha uma agência de notícias e um escritório de vendas de publicidade em Canyon Lake Drive em Rapid City, o controle principal e a maioria das operações internas são baseadas nos estúdios da KELO-TV. Como Rapid City está localizada no fuso horário das montanhas, o horário nobre da KCLO-TV começa às 18h. em vez do usual 19:00 comece para o resto do horário das montanhas, ou no horário central, onde as outras estações do KELOLAND Media Group estão localizadas.

KELO-TV foi ao ar em 19 de maio de 1953 como a primeira estação de televisão de Dakota do Sul. Era propriedade da Midcontinent Media, conglomerado de teatro e radiodifusão, junto com a rádio KELO (AM 1320 e 92,5 FM). Era uma afiliada principal da NBC, mas também exibia programas da ABC, CBS e DuMont. Depois que a KSOO-TV (agora KSFY-TV) assinou em 1960, a KELO-TV mudou sua afiliação primária para a CBS e permaneceu com essa rede desde então.

Logo após a assinatura do KELO-TV, a Federal Communications Commission (FCC) transformou o leste de Dakota do Sul, o sudoeste de Minnesota e o noroeste de Iowa em um mercado gigante de televisão. Mais tarde, na década de 1950, o Midcontinent começou a assinar estações de satélite da KELO-TV para atender sua vasta área de cobertura. A KDLO-TV em Florença (originalmente licenciada para Garden City) foi a primeira das estações de satélite a ir ao ar em 27 de setembro de 1955, seguida pela KPLO-TV, licenciada para Reliance e servindo a capital do estado de Dakota do Sul, Pierre, em 15 de julho, 1957.

A KELO-TV se expandiu para o oeste de Dakota do Sul em 1981, quando assinou com a K15AC (canal 15), uma tradutora da KPLO-TV, para servir a Rapid City. Em 28 de novembro de 1988, ele foi atualizado para um semi-satélite de potência total como KCLO. Rapid City era uma das poucas áreas do país sem serviço completo das três redes principais.

KELO era o lar de Capitão 11, um show infantil popular na área, de 1955 a 1996. O capitão 11 era Dave Dedrick, o meteorologista de longa data da estação. Ele havia sido uma personalidade popular do rádio antes de KELO ir ao ar.

O Canal 11 foi originalmente transmitido de uma torre de 575 pés (175 m) perto de Shindler, Dakota do Sul. Em 20 de setembro de 1955, foi destruído por uma forte tempestade de vento - que se acredita ser um tornado. Os engenheiros da estação colocaram a estação de volta ao ar em 48 horas - bem a tempo para a World Series. [1] Em 1956, a estação ergueu uma torre de 315 m (1.032 pés) no mesmo local, expandindo sua área de cobertura para a maior parte do leste de Dakota do Sul. Em 1967, a KELO-TV mudou-se para uma nova torre de 2.032 pés (619 m) perto de Rowena, compartilhada com a KSFY. A torre Shindler ainda é usada como backup.

Em 24 de junho de 1968, um avião da North Central prendeu um cabo de segurança na velha torre Rowena, derrubando-a. Felizmente, o avião pousou em segurança sem ferimentos. Os engenheiros da KELO-TV colocaram a estação de volta ao ar em três dias, da velha torre em Shindler. A torre Rowena foi rapidamente reconstruída. [1]

Em 11 de janeiro de 1975, a torre KELO-TV foi destruída por uma forte tempestade de inverno. Em poucas horas, a estação estava de volta ao ar de Shindler. [2] A torre foi reconstruída novamente em Rowena e tornou-se operacional em 19 de dezembro de 1975. O local de Rowena é às vezes chamado de "Triângulo das Bermudas" devido aos inúmeros desabamentos.

Nos anos que se seguiram, a torre da KDLO-TV desabou e a KELO-TV perdeu outros sites de microondas e tradutores devido a tempestades e outros motivos. [2] A torre da KPLO-TV desabou em 22 de janeiro de 2010 em uma forte tempestade de gelo. Ele voltou ao ar em 19 de março de 2010. Por um tempo, porém, operou em baixa potência, deixando Pierre sem sinal. A FCC posteriormente emitiu uma licença de construção para um tradutor de preenchimento de baixa potência no canal 29 em Pierre.

Em 25 de novembro de 1986, a KELO-TV começou a transmitir sua programação em estéreo. Em 1995, Midcontinent Media vendeu KELO-TV para Young Broadcasting a venda foi aprovada pela FCC em 31 de maio de 1996. A estação comemorou seu 50º aniversário em 19 de maio de 2003.

Uma tempestade de gelo no final da temporada em 6 de abril de 1997 causou o colapso do mastro KXJB-TV em Traill County, Dakota do Norte. Como resultado, vários sistemas de cabo no leste de Dakota do Norte e noroeste de Minnesota foram incapazes de receber a programação da CBS. Alguns sistemas de cabo substituíram temporária ou permanentemente KXJB-TV por KDLO-TV. (A programação da CBS no leste de Dakota do Norte mudou desde então para KXJB-LD e KVLY-DT2.)

Em 1999, a estação recebeu o prêmio da National Association of Broadcasters Friend in Needs Television por seu excelente serviço em face de desastres naturais. [3]

Em 6 de junho de 2013, a Young Broadcasting anunciou que se fundiria com a Media General. [4] A fusão foi aprovada em 8 de novembro, depois que os acionistas da Media General a aprovaram um dia antes [5], ela foi concluída em 12 de novembro. [6]

Venda para Nexstar Edit

Em 27 de janeiro de 2016, o Nexstar Broadcasting Group anunciou que havia chegado a um acordo para adquirir a Media General, incluindo KELO-TV, [7] com a venda sendo concluída em 17 de janeiro de 2017, trazendo KELO-TV sob propriedade comum com afiliado ABC KCAU-TV em Sioux City, Iowa. [8]


Conteúdo

O mastro está localizado a 3 milhas (4,8 km) a oeste de Blanchard, Dakota do Norte, a meio caminho entre Fargo e Grand Forks. Tornou-se a estrutura artificial mais alta e a primeira estrutura feita pelo homem a exceder 2.000 pés (610 m) de altura, após a conclusão de sua construção em 13 de agosto de 1963.

A torre foi construída pela Hamilton Erection Company de York, Carolina do Sul e Kline Iron and Steel, e levou trinta dias para ser concluída, a um custo de aproximadamente $ 500.000 [2] (cerca de $ 4,23 milhões hoje [3]). A construção foi concluída em 13 de agosto de 1963. [4]

Propriedade da Gray Television de Atlanta, Geórgia, a torre transmite a 356 kW no canal 44 da estação de televisão KVLY-TV (canal 11 PSIP, uma afiliada da NBC / CBS), com sede em Fargo, Dakota do Norte. A torre fornece uma área de transmissão de aproximadamente 9.700 milhas quadradas (25.000 km 2), que é um raio de cerca de 55,6 milhas (89,5 km). Devido ao reempacotamento do espectro, o KVLY transmite no canal UHF 36 e mapeia para o canal virtual 11 por meio do PSIP. O tradutor K28MA-D da afiliada CBS / CW + KXJB-LD também transmite nesta torre a 15 kW no canal 28 de UHF (também seu canal virtual).

Quando o mastro foi construído, as letras de chamada da estação de televisão para a qual foi construído foram alteradas para KTHI, o "HI" referindo-se à altura do mastro. O topo pode ser alcançado por um elevador de serviço para duas pessoas (construído pela Park Manufacturing de Charlotte, Carolina do Norte) ou escada.

A torre consiste em duas partes: uma torre de treliça de 1.950 pés (590 m) [5], encimada pelo conjunto de antenas transmissoras de 113 pés (34 m). A altura total de ambos é de 2.063 pés (629 m). A antena pesa 9.000 libras (4,1 t), a torre de treliça pesa 855.500 libras (388,0 t), dando um peso total de 864.500 libras (392,1 t). Ele ocupa 160 acres (65 ha) de terra com suas âncoras. [6] [7] Sua altura acima do nível médio do mar é de 3.038 pés (926 m).

Algum tempo após sua conclusão, a Federal Communications Commission (FCC) e a Federal Aviation Administration (FAA) impuseram uma política que afirma: "Embora não haja um limite de altura absoluto para torres de antenas, ambas as agências estabeleceram uma presunção refutável contra estruturas acima de 2.000 pés acima do nível do solo. " A FCC e a FAA podem aprovar uma estrutura mais alta em "casos excepcionais". [8]


Linha do tempo: Ataque na América

8h45 O vôo 11 da American Airlines, que transportava 92 pessoas de Boston para Los Angeles, bate na torre norte do World Trade Center.

9h03 O voo 175 da United Airlines, que transportava 65 pessoas de Boston para Los Angeles, bate na torre sul do World Trade Center.

9h31 O presidente Bush chama os acidentes de "aparente ataque terrorista ao nosso país".

9h40 Negociação em Wall Street cancelada.

9h43 O voo 77 da American Airlines, que transportava 64 pessoas de Washington para Los Angeles, cai perto do Pentágono.

Notícias populares

9h48 O Capitólio e a ala oeste da Casa Branca foram evacuados.

9h49 A Federal Aviation Administration proíbe decolagens de aeronaves em todo o país. Vôos internacionais em andamento devem aterrissar no Canadá.

9h50 No World Trade Center, a torre norte desmorona.

10:29 Dois World Trade Center, a torre sul desmorona.

10:37 Autoridades confirmam que o voo 93 da United Airlines, a caminho de São Francisco vindo de Newark, N.J., caiu a 80 milhas a sudeste de Pittsburgh. Nenhuma das 45 pessoas a bordo teria sobrevivido.

10-11: 30 Prédios do governo em todo o país são evacuados, incluindo o Capitólio e a Casa Branca. As Nações Unidas fecharam. A Securities and Exchange Commission fecha todos os mercados financeiros dos EUA naquele dia. O prefeito da cidade de Nova York, Rudolph Giuliani, pede a evacuação da parte baixa de Manhattan.

13h20 Bush deixa a Base Aérea de Barksdale, Louisiana, para um local seguro e não revelado.

14h51 A Marinha envia destruidores de mísseis e outros equipamentos para Nova York e Washington.

17:25 Sete colapsos do World Trade Center.

& copyMMI The Associated Press. Todos os direitos reservados. Este material não pode ser publicado, transmitido, reescrito ou redistribuído

Publicado pela primeira vez em 11 de setembro de 2001 / 19h18

& cópia 2001 The Associated Press. Todos os direitos reservados. Este material não pode ser publicado, transmitido, reescrito ou redistribuído.


Por que o WTC Towers desabou

Uma espessa fumaça negra se agita em nuvens venenosas enquanto o World Trade Center é engolido pelas chamas.

Como Bob Orr, correspondente da CBS News relatos, o incêndio, uma recriação elaborada do local exato em que a torre norte foi atingida, está no centro de uma investigação de dois anos sobre o motivo da queda das torres gêmeas.

Enquanto o fogo queima dentro do laboratório, do lado de fora ficam os restos mortais dos arranha-céus caídos. Os investigadores, vasculharam toneladas de destroços, combinaram números de série marcados e identificaram de forma incrível as colunas exatas atingidas pelos aviões.

"Esta peça em particular foi atingida pela parte superior da fuselagem", diz Frank Gayle, metalúrgico do Instituto Nacional de Padrões e Tecnologia. "Vemos como os parafusos funcionaram, tudo ao longo dessa linha."

Eles pegaram pequenas amostras do aço e as dispararam através de um canhão de ar para calcular com precisão os danos causados ​​pelos jatos sequestrados.

Os testes sugerem fortemente que os ataques do avião não derrubaram as torres. E não foram os milhares de galões de combustível de aviação que os aviões carregavam.

Notícias populares

"O próprio combustível foi consumido em questão de minutos", disse Shyam Sunder, investigador-chefe do NIST na sonda WTC.

Portanto, a crença popular de que todo esse combustível tornou o colapso do prédio inevitável não é verdade, diz Sunder.

Para descobrir por que os edifícios realmente desabaram, os cientistas do NIST recriaram o 96º andar, completo com computadores, tapetes, móveis e papel. Em seguida, eles atearam fogo. Agora, os investigadores estão perto de provar que foi esse material de escritório comum queimando em um incêndio alimentado pelo oxigênio das janelas quebrando continuamente que, no final das contas, fez com que o aço cedesse.

"O aço tende a amolecer ou enfraquecer e se tornar mais parecido com Playdough quando você aquece", diz Sunder.

Os investigadores apresentarão seu relatório final neste outono. Eles farão recomendações abrangentes com o objetivo de tornar os edifícios mais capazes de resistir a eventos catastróficos e solicitarão a melhoria das evacuações com o objetivo de sobreviver ao impensável.


Conteúdo

Após a conclusão em 1973, as Torres Gêmeas foram brevemente os edifícios mais altos do mundo e, na época dos ataques terroristas, ainda estavam entre os cinco primeiros. O One World Trade Center (WTC 1), a "Torre Norte", era, a 1.368 pés (417 m), seis pés mais alto que o Two World Trade Center (WTC 2), a "Torre Sul", que tinha 1.362 pés (415 m) de altura . Na época dos ataques, apenas as Torres Petronas, então recentemente concluídas, em Kuala Lumpur, na Malásia, e a Torre Willis (conhecida então como Torre Sears) em Chicago eram mais altas. [2] Construídas com um design inovador que maximizava o espaço interior, as torres tinham uma alta relação resistência / peso, pois utilizavam um novo design de "tubo com estrutura" que exigia 40 por cento menos aço do que os arranha-céus tradicionais com estrutura de aço. [3] Além disso, no topo do WTC 1 estava uma antena de telecomunicações de 362 pés (110 m) que foi erguida em 1978 trazendo a altura total dessa torre para 1.730 pés (530 m), embora como uma adição não estrutural, a antena não era oficialmente contado.

Projeto estrutural

As torres foram projetadas como estruturas tubulares emolduradas, o que proporcionou aos inquilinos plantas baixas abertas, não interrompidas por colunas ou paredes. Os edifícios eram quadrados e com 207 pés (63 m) de cada lado, mas tinham cantos chanfrados de 6 pés e 11 polegadas (2,11 metros), tornando o exterior de cada edifício cerca de 210 pés (64 m) de largura. [4] Numerosas colunas de perímetro estreitamente espaçadas forneceram grande parte da resistência à estrutura, juntamente com a carga de gravidade compartilhada com as colunas de caixa de aço do núcleo. [5] Acima do décimo andar, havia 59 colunas de perímetro ao longo de cada face do edifício espaçadas de 3 pés e 4 polegadas (1,02 metros) no centro. [5] Enquanto as torres eram quadradas, os núcleos internos eram retangulares e eram sustentados por 47 colunas que ocupavam toda a altura de cada torre. [4] Todos os elevadores e escadarias estavam localizados no núcleo, deixando um grande espaço livre de colunas entre ele e o perímetro que era interligado por treliças de piso pré-fabricadas. [5] Como o núcleo era retangular, isso criava uma distância de vão longo e curto para as colunas do perímetro.

Os pisos consistiam em lajes de concreto leve de 10 cm de espessura colocadas em uma plataforma de aço canelada. [4] Uma grade de treliças de ponte leves e treliças principais sustentava os pisos com conexões de cisalhamento à laje de concreto para ação mista. [5] As treliças tinham um vão de 60 pés (18 m) nas áreas de vão longo e 35 pés (11 m) nas áreas de curto vão. As treliças conectavam-se ao perímetro em colunas alternadas e, portanto, tinham centros de 2,1 m (6,8 pés). As cordas superiores das treliças foram aparafusadas a assentos soldados aos spandrels no lado do perímetro e um canal soldado às colunas internas da caixa no lado do núcleo. Os pisos foram conectados às placas de spandrel do perímetro com amortecedores viscoelásticos, o que ajudou a reduzir a quantidade de oscilação sentida pelos ocupantes do edifício. [5]

As torres também incorporaram uma "treliça de chapéu" ou "treliça de estabilizador" localizada entre o 107º e 110º andares, que consistia em seis treliças ao longo do eixo longo do núcleo e quatro ao longo do eixo curto. [4] Este sistema de treliça permitiu a redistribuição de carga otimizada dos diafragmas do piso entre o perímetro e o núcleo, com melhor desempenho entre os diferentes materiais de aço flexível e concreto rígido, permitindo que as armações de momento transferissem oscilação para compressão no núcleo, que também suportava principalmente o torre de transmissão. Essas treliças foram instaladas em cada edifício para suportar futuras torres de transmissão, mas apenas a torre norte foi finalmente equipada com uma. [4]

Avaliações para impacto da aeronave

Embora estudos de incêndio e até mesmo uma análise dos impactos dos impactos de aeronaves a jato de baixa velocidade tenham sido realizados antes de sua conclusão, o escopo completo desses estudos não existe mais. No entanto, como o fogo nunca havia causado o colapso de um arranha-céu e os impactos da aeronave foram considerados em seu projeto, sua destruição inicialmente foi uma surpresa para alguns na comunidade de engenheiros. [6]

Os engenheiros estruturais que trabalhavam no World Trade Center consideraram a possibilidade de uma aeronave colidir com o prédio. Em julho de 1945, um bombardeiro B-25 que se perdeu no nevoeiro colidiu com o 79º andar do Empire State Building. [7] Um ano depois, um C-45F Expeditor colidiu com o prédio 40 de Wall Street. Mais uma vez, acreditou-se que o nevoeiro foi o fator que contribuiu para a colisão. [8] Leslie Robertson, um dos engenheiros-chefe trabalhando no projeto do World Trade Center, afirmou que considerou o cenário do impacto de um Boeing 707, que poderia se perder no nevoeiro e voar a velocidades relativamente baixas enquanto buscava para pousar nos aeroportos JFK ou Newark. [9] Em uma entrevista à BBC dois meses após o colapso do prédio, Robertson afirmou que, "com o 707, a carga de combustível não foi considerada no projeto, não sei como poderia ter sido considerada." Na entrevista, Robertson afirmou que a principal diferença entre os estudos de projeto e o evento que acabou por causar o colapso das torres se deveu à velocidade do impacto, que aumentou muito a energia absorvida, e nunca foi considerada durante o processo de construção. [10]

Durante a investigação sobre o colapso, o Instituto Nacional de Padrões e Tecnologia (NIST) obteve um white paper de três páginas que afirmava que os edifícios sobreviveriam a um impacto de aeronave de um Boeing 707 ou DC 8 voando a 600 milhas por hora (970 km / h). [11] Em 1993, John Skilling, engenheiro estrutural chefe do WTC, durante uma entrevista realizada após o atentado ao World Trade Center de 1993, comentou: "Nossa análise indicou que o maior problema seria o fato de que todo o combustível (do avião) seria despejar no prédio. Haveria um incêndio horrível. Muita gente morreria ”, disse. "A estrutura do prédio ainda estaria lá." [12] Em seu relatório, o NIST afirmou que a capacidade técnica para realizar uma simulação rigorosa do impacto da aeronave e incêndios decorrentes é um desenvolvimento recente, e que a capacidade técnica para tal análise teria sido bastante limitada na década de 1960. [13] [nota 1] Em seu relatório final sobre os colapsos, o NIST afirmou que não foi possível encontrar nenhuma documentação que examinasse o impacto de um jato de alta velocidade ou de um incêndio em grande escala alimentado por combustível de aviação. [14]

À prova de fogo

Até meados da década de 1970, o uso de amianto para proteção contra incêndio era comum na indústria da construção. No entanto, em abril de 1970, o Departamento de Recursos Aéreos da Cidade de Nova York ordenou que os empreiteiros que construíam o World Trade Center parassem a pulverização de amianto como material isolante. [15]

Após o bombardeio de 1993, as inspeções constataram que a proteção contra incêndio era deficiente. [16] Antes dos colapsos, os proprietários das torres, a Autoridade Portuária de Nova York e Nova Jersey, estavam em processo de adição de proteção contra incêndio, mas só haviam sido concluídos em 18 andares em 1 WTC, incluindo todos os andares afetados por o impacto da aeronave e incêndios, e em 13 andares em 2 WTC, embora nenhum tenha sido diretamente afetado pelo impacto da aeronave. [17]

O NIST concluiu que o impacto da aeronave removeu uma parte significativa da proteção contra incêndio, contribuindo para o colapso dos edifícios. No WTC 1, o impacto removeu o isolamento de 43 das 47 colunas centrais em mais de um andar, bem como das treliças do piso em um espaço de 60.000 pés quadrados (5.600 m 2). No WTC 2, o impacto removeu o isolamento de 39 das 47 colunas em vários andares e das treliças do piso, abrangendo uma área de 7.400 m 2 (80.000 pés quadrados). [14]

Após os colapsos, Leslie Robertson afirmou: "Até onde sabemos, pouco se sabia sobre os efeitos de um incêndio de tal aeronave e nenhum projeto foi preparado para essa circunstância. Na verdade, naquela época, nenhum sistema à prova de fogo estava disponível para controlar os efeitos de tais incêndios. " [9]

Impactos de aeronaves e incêndios resultantes

Durante os ataques de 11 de setembro, quatro equipes de terroristas da Al-Qaeda sequestraram quatro aviões a jato diferentes. Dois desses jatos, American Airlines Flight 11 e United Airlines Flight 175, ambos Boeing 767s, foram sequestrados após a decolagem do Aeroporto Internacional Logan de Boston. Em seus momentos finais, o vôo 11 da American Airlines voou para o sul sobre Manhattan e caiu a cerca de 440 milhas por hora (710 km / h) na fachada norte da Torre Norte (WTC 1) às 8h46, impactando entre o 93º e o 99º andares. Dezessete minutos depois, o voo 175 da United Airlines se aproximou do sudoeste, sobre o porto de Nova York, e bateu na fachada sul da Torre Sul (WTC 2) às 9h02 entre o 77º e 85º andares a 540 milhas por hora (870 km / h).

Além de cortar várias colunas de suporte de carga no perímetro e infligir outros danos estruturais, os impactos incendiaram milhares de galões de combustível de aviação, que por sua vez incendiou combustíveis de escritório. Cerca de um terço do combustível foi consumido no impacto inicial e na bola de fogo resultante. [nota 2] [18] Algum combustível do impacto viajou por pelo menos um poço de elevador e explodiu no 78º andar da Torre Norte, bem como no saguão principal. [19] A construção leve e a natureza oca das estruturas permitiram que o combustível de aviação penetrasse bem dentro das torres, acendendo muitos grandes incêndios simultaneamente em uma ampla área dos pisos impactados. O combustível dos aviões queimou no máximo por alguns minutos, mas o conteúdo dos edifícios queimou na próxima hora ou hora e meia. [20]

Resposta de emergência e evacuação

Quase todas as mortes nas Torres Gêmeas ocorreram nas zonas acima dos pontos de impacto das aeronaves. Como a Torre Norte havia sido atingida diretamente no meio da estrutura, as três escadas no núcleo da torre foram todas danificadas ou bloqueadas por destroços, impedindo a fuga para os andares inferiores. Na Torre Sul, o impacto foi ligeiramente fora do centro da seção central da torre e a escada A na porção noroeste do núcleo central foi apenas parcialmente bloqueada, e 14 a 18 civis conseguiram escapar do ponto de impacto da aeronave e andares acima disso. O número exato de pessoas que morreram e onde em alguns casos não é conhecido com precisão, no entanto, o relatório do Instituto Nacional de Padrões e Tecnologia indicou que um total de 1.402 civis morreram no ponto de impacto na Torre Norte ou acima dele, com centenas de pessoas mortas em o momento do impacto. Na Torre Sul, 614 civis morreram nos andares impactados e nos andares superiores. Menos de 200 das mortes de civis ocorreram nos andares abaixo dos pontos de impacto, mas todos os 147 passageiros civis e tripulantes das duas aeronaves, bem como todos os 10 terroristas, morreram, junto com pelo menos 18 pessoas no solo e em estruturas adjacentes. [21]

Ao todo, o pessoal de emergência morto no colapso incluiu 343 bombeiros da cidade de Nova York (FDNY) e 71 policiais, incluindo 23 membros do Departamento de Polícia da cidade de Nova York (NYPD), 37 membros do Departamento de Polícia da Autoridade Portuária (PAPD), cinco membros do Escritório de Execução Fiscal do Estado de Nova York (OTE), três oficiais do Escritório de Administração do Tribunal do Estado de Nova York (OCA), um bombeiro do Corpo de Bombeiros da Cidade de Nova York (FDNY) que jurou poderes de aplicação da lei ( e também estava entre os 343 membros do FDNY mortos), um membro do Federal Bureau of Investigation (FBI) e um membro do Serviço Secreto dos Estados Unidos (USSS). O número total de mortos de civis e não civis é estimado em 2.606 pessoas.

A destruição das Torres Gêmeas foi chamada de "o paradigma mais infame" do colapso progressivo. [6] Eles começaram com a falha local de alguns componentes estruturais e progrediram para abranger toda a estrutura. [22] Tais colapsos são caracterizados pela "separação dos componentes estruturais (incluindo elementos não portadores de carga), a liberação de energia gravitacional e a ocorrência de forças de impacto." A força de impacto vertical fornece a ação de propagação, as forças principais são paralelas e a transferência de carga primária é serial. [23] O elemento-chave na estrutura que falhou foi constituído pela combinação de "membros de suporte de carga verticais de um andar inteiro." Com exceção dos andares superiores do edifício, que não teriam liberado energia gravitacional suficiente para ocasionar um colapso total, os colapsos poderiam ter começado com o fracasso de qualquer história. [24]

Nessas condições, as torres desabaram simetricamente e mais ou menos diretamente para baixo, embora tenha havido alguma inclinação do topo das torres e uma quantidade significativa de precipitação para os lados. Em ambos os casos, a seção do edifício que havia sido danificada pelos aviões falhou, o que permitiu que os andares acima da zona de impacto caíssem sobre a estrutura não danificada abaixo. À medida que o colapso avançava, poeira e destroços podiam ser vistos saindo das janelas vários andares abaixo da destruição que avançava, causada pela súbita corrente de ar comprimido sob os níveis superiores descendentes.

Durante cada desabamento, grandes porções das colunas perimetrais e possivelmente dos núcleos ficavam sem nenhum apoio lateral, fazendo com que caíssem lateralmente para o exterior, empurradas pela crescente pilha de entulho. O resultado foi que as paredes descascaram e se separaram dos edifícios por uma grande distância (cerca de 500 pés em alguns casos), atingindo outros edifícios vizinhos e iniciando incêndios que mais tarde levariam ao colapso do Edifício 7. Algumas conexões quebraram como os parafusos quebraram, deixando muitos painéis espalhados aleatoriamente. [25] Os primeiros fragmentos das paredes externas da Torre Norte em colapso atingiram o solo 11 segundos após o início do colapso, e partes da Torre Sul após 9 segundos. As porções inferiores dos núcleos de ambos os edifícios (60 andares do WTC 1 e 40 andares do WTC 2) permaneceram de pé por até 25 segundos após o início do colapso inicial, antes de também entrarem em colapso. [13]

Iniciação de colapso

Depois que os aviões atingiram os prédios, mas antes que eles desabassem, os núcleos de ambas as torres consistiam em três seções distintas. Acima e abaixo dos pisos de impacto, os núcleos consistiam no que eram essencialmente duas caixas rígidas - o aço nessas seções não estava danificado e não havia sofrido aquecimento significativo. A seção entre eles, no entanto, havia sofrido danos significativos e, embora não estivessem quentes o suficiente para derretê-lo, os incêndios estavam enfraquecendo o aço estrutural.

Como resultado, as colunas centrais estavam sendo lentamente esmagadas, sustentando a deformação plástica e por fluência com o peso dos pisos acima. Conforme a seção superior tentava se mover para baixo, no entanto, a treliça do chapéu redistribuiu a carga para as colunas do perímetro. Enquanto isso, as colunas e pisos do perímetro também estavam sendo enfraquecidos pelo calor dos incêndios, e conforme os pisos começaram a ceder, eles puxaram as paredes externas para dentro. "A perda de capacidade de carga vertical resultante foi limitada a alguns andares, mas se estendeu por toda a seção transversal de cada torre." [26] No caso do 2 WTC, a face leste finalmente se dobrou, transferindo suas cargas de volta para o núcleo com falha através da treliça do chapéu e iniciando o colapso. Mais tarde, a parede sul de 1 WTC dobrou-se da mesma maneira e com consequências semelhantes. [27]

Colapso progressivo total

Os sistemas estruturais respondem de forma muito diferente às cargas estáticas e dinâmicas e, embora as torres tenham sido projetadas para suportar um peso enorme em condições normais, eles forneceram pouca resistência à massa móvel da seção acima dos pisos danificados. Em ambos os casos, os colapsos começaram com a queda da seção superior através da altura de pelo menos um andar (cerca de três metros ou dez pés), mas uma queda de apenas meio metro (cerca de 20 polegadas) teria liberado a energia necessária para começar um colapso imparável. [28]

A partir daí, o colapso passou por duas fases. Durante o esmagar fase, o bloco superior destruiu a estrutura abaixo em uma série progressiva de falhas de coluna, aproximadamente um andar de cada vez. Cada falha começou com o impacto do bloco superior nas colunas da seção inferior, mediado por uma camada crescente de entulho consistindo principalmente de concreto das lajes do piso. A energia de cada impacto foi "reintroduzida na estrutura no impacto subsequente, concentrada [d] nos elementos de suporte de carga diretamente afetados pelo impacto." [23] Isso entortou as colunas da história imediatamente abaixo do avanço da destruição até o próximo ponto de apoio lateral, geralmente as treliças do piso da história dada. Depois que as colunas se dobraram, o bloco ficou mais uma vez sem sustentação e caiu ao longo da distância daquela história, novamente impactando as colunas da história abaixo, que então se dobraram da mesma maneira.

Isso se repetiu até que o bloco superior alcançou o solo e o esmagamento fase começou. Aqui, também, as colunas dobraram uma história por vez, agora começando de baixo. À medida que cada história falhava, o bloco restante caía da altura da história, para o próximo, que também era esmagado, até que o telhado finalmente atingiu o solo. [6] O processo se acelerou ao longo e, no final, cada história estava sendo esmagada em menos de um décimo de segundo. [28]

Colapso da torre sul

Enquanto os incêndios continuavam a queimar, os ocupantes presos nos andares superiores da Torre Sul forneceram informações sobre as condições aos despachantes do 9-1-1. Às 9h37, um ocupante do 105º andar da Torre Sul relatou que os andares abaixo dele "no andar de 90 e poucos" desabaram. [29] A unidade de aviação do Departamento de Polícia da Cidade de Nova York também transmitiu informações sobre a deterioração das condições dos edifícios aos comandantes da polícia. [30] Apenas 14 pessoas escaparam de cima da zona de impacto da Torre Sul depois que ela foi atingida (incluindo Stanley Praimnath, que viu o avião vindo em sua direção), e apenas quatro dos andares acima dela. Eles escaparam pela escada A, a única escada que permaneceu intacta após o impacto. Vários operadores de linhas diretas da polícia que receberam ligações de indivíduos dentro da Torre Sul não foram bem informados sobre a situação, que se desenrolou rapidamente. Muitos operadores disseram aos chamadores para não descerem da torre por conta própria, embora agora se acredite que a Stairwell A era provavelmente transitável no ponto de impacto e acima dele. [31] Às 9h52, a unidade de aviação da NYPD relatou pelo rádio que "pedaços grandes podem estar caindo do topo do WTC 2. Grandes pedaços estão pendurados lá". [29] Com os avisos, o NYPD emitiu ordens para seus oficiais evacuarem. Durante a resposta de emergência, houve comunicação mínima entre o NYPD e o Corpo de Bombeiros de Nova York (FDNY), e os despachantes 9-1-1 sobrecarregados não repassaram informações aos comandantes do FDNY no local. Às 9h59, a Torre Sul desabou, 57 minutos após ser atingida.

Colapso da torre norte

Após o colapso da Torre Sul, os helicópteros da NYPD transmitiram informações sobre a deterioração das condições da Torre Norte. Às 10h20, a unidade de aviação da NYPD relatou que "o topo da torre pode estar inclinado", e um minuto depois informou que a Torre Norte "está dobrando no canto sudoeste e inclinando-se para o sul". At 10:28 a.m., the aviation unit reported that "the roof is going to come down very shortly" [29] and indeed, the North Tower collapsed immediately thereafter, at 10:28 a.m., after burning for 102 minutes.

After the South Tower collapsed, FDNY commanders issued orders for firefighters in the North Tower to evacuate. Due to radio communications problems, firefighters inside the towers did not hear the evacuation order from their supervisors on the scene, and most were unaware that the other tower had collapsed. [32] Three-hundred forty three firefighters died in the Twin Towers, as a result of the collapse of the buildings. [33] [34] [35] No one was able to escape the North Tower from the impact zone or above, as all stairwells and elevator shafts on those floors were destroyed or blocked. [36] After the collapse, light dust reached as far as the Empire State Building, located 2.93 miles (4.72 km) away.

Building 7 collapse

As the North Tower collapsed, heavy debris hit 7 World Trade Center, causing damage to the south face of the building [37] and starting fires that continued to burn throughout the afternoon. [38] Structural damage occurred to the southwest corner between Floors 7 and 17 and on the south facade between Floor 44 and the roof other possible structural damage includes a large vertical gash near the center of the south facade between Floors 24 and 41. [38] The building was equipped with a sprinkler system, but had many single-point vulnerabilities for failure: the sprinkler system required manual initiation of the electrical fire pumps, rather than being a fully automatic system the floor-level controls had a single connection to the sprinkler water riser and the sprinkler system required some power for the fire pump to deliver water. Also, water pressure was low, with little or no water to feed sprinklers. [39] [40]

Some firefighters entered 7 World Trade Center to search the building. They attempted to extinguish small pockets of fire, but low water pressure hindered their efforts. [41] Fires burned into the afternoon on the 11th and 12th floors of 7 World Trade Center, the flames visible on the east side of the building. [42] [43] During the afternoon, fire was also seen on floors 6–10, 13–14, 19–22, and 29–30. [37] In particular, the fires on floors 7 through 9 and 11 through 13 continued to burn out of control during the afternoon. [44] At approximately 2:00 pm, firefighters noticed a bulge in the southwest corner of 7 World Trade Center between the 10th and 13th floors, a sign that the building was unstable and might cave to one side or "collapse". [45] During the afternoon, firefighters also heard creaking sounds coming from the building and issued uncertain reports about damage in the basement. [46] Around 3:30 pm FDNY Chief Daniel A. Nigro decided to halt rescue operations, surface removal, and searches along the surface of the debris near 7 World Trade Center and evacuate the area due to concerns for the safety of personnel. [47] At 5:20:33 pm EDT on September 11, 2001, 7 World Trade Center started to collapse, with the crumble of the east mechanical penthouse, while at 5:21:10 pm EDT the entire building collapsed completely. [48] [49] There were no casualties associated with the collapse.

When 7 World Trade Center collapsed, debris caused substantial damage and contamination to the Borough of Manhattan Community College's Fiterman Hall building, located adjacent at 30 West Broadway, to the extent that the building was not salvageable. In August 2007, Fiterman Hall was scheduled for dismantling. [50] A revised plan called for demolition in 2009 and completion of the new Fiterman Hall in 2012, at a cost of $325 million. [51] [52] The building was finally demolished in November 2009 and construction of its replacement began on December 1, 2009. [53] The adjacent Verizon Building, an Art Deco building constructed in 1926, had extensive damage to its east facade from the collapse of 7 World Trade Center, though it was successfully restored at a cost of US$1.4 billion. [54]

Other buildings

Many of the surrounding buildings were also either damaged or destroyed as the towers fell. 5 WTC endured a large fire and a partial collapse of its steel structure and was torn down. Other buildings destroyed include St. Nicholas Greek Orthodox Church, Marriott World Trade Center (Marriott Hotel 3 WTC), South Plaza (4 WTC), and U.S. Customs (6 WTC). The World Financial Center buildings, 90 West Street, and 130 Cedar Street suffered fires. The Deutsche Bank Building, the Verizon Building, and World Financial Center 3 had impact damage from the towers' collapse, [55] as did 90 West Street. [56] One Liberty Plaza survived structurally intact but sustained surface damage including shattered windows. 30 West Broadway was damaged by the collapse of 7 WTC. The Deutsche Bank Building, which was covered in a large black "shroud" after September 11 to cover the building's damage, was deconstructed because of water, mold, and other severe damage caused by the neighboring towers' collapse. [57] [58] Many works of art were destroyed in the collapse.

Initial opinions and analysis

In the immediate aftermath of the attacks, numerous structural engineers and experts spoke to the media, describing what they thought caused the towers to collapse. Abolhassan Astaneh-Asl, a structural engineering professor at the University of California at Berkeley, explained that the high temperatures in the fires weakened the steel beams and columns, causing them to become "soft and mushy", and eventually they were unable to support the structure above. Astaneh-Asl also suggested that the fireproofing became dislodged during the initial aircraft impacts. He also explained that, once the initial structural failure occurred, progressive collapse of the entire structure was inevitable. [59] César Pelli, who designed the Petronas Towers in Malaysia and the World Financial Center in New York, remarked, "no building is prepared for this kind of stress." [60]

On September 13, 2001, Zdeněk P. Bažant, professor of civil engineering and materials science at Northwestern University, circulated a draft paper with results of a simple analysis of the World Trade Center collapse. Bažant suggested that heat from the fires was a key factor, causing steel columns in both the core and the perimeter to weaken and experience deformation before losing their carrying capacity and buckling. Once more than half of the columns on a particular floor buckled, the overhead structure could no longer be supported and complete collapse of the structures occurred. Bažant later published an expanded version of this analysis. [61] Other analyses were conducted by MIT civil engineers Oral Buyukozturk and Franz-Josef Ulm, who also described a collapse mechanism on September 21, 2001. [62] They later contributed to an MIT collection of papers on the WTC collapses edited by Eduardo Kausel called The Towers Lost and Beyond. [63]

Immediately following the collapses, there was some confusion about who had the authority to carry out an official investigation. While there are clear procedures for the investigation of aircraft accidents, no agency had been appointed in advance to investigate building collapses. [64] A team was quickly assembled by the Structural Engineers Institute of the American Society of Civil Engineers, led by W. Gene Corley, Senior Vice President of CTLGroup. It also involved the American Institute of Steel Construction, the American Concrete Institute, the National Fire Protection Association, and the Society of Fire Protection Engineers. [65] ASCE ultimately invited FEMA to join the investigation, which was completed under the auspices of the latter. [65]

The investigation was criticized by some engineers and lawmakers in the U.S. It had little funding, no authority to demand evidence, and limited access to the WTC site. One major point of contention at the time was that the cleanup of the WTC site was resulting in the destruction of the majority of the buildings' steel components. [66] Indeed, when NIST published its final report, it noted "the scarcity of physical evidence" that it had had at its disposal to investigate the collapses. Only a fraction of a percent of the buildings remained for analysis after the cleanup was completed: some 236 individual pieces of steel, although 95% of structural beams and plates and 50% of the reinforcement bars were recovered. [67]

FEMA published its report in May 2002. While NIST had already announced its intention to investigate the collapses in August of the same year, by September 11, 2002 (a year after the disaster), there was growing public pressure for a more thorough investigation. [68] Congress passed the National Construction Safety Team bill in October 2002, giving NIST the authority to conduct an investigation of the World Trade Center collapses. [69]

FEMA building performance study

FEMA suggested that fires in conjunction with damage resulting from the aircraft impacts were the key to the collapse of the towers. Thomas Eagar, Professor of Materials Engineering and Engineering Systems at MIT, described the fires as "the most misunderstood part of the WTC collapse". This is because the fires were originally said to have "melted" the floors and columns. [70] Jet fuel is essentially kerosene and would have served mainly to ignite very large, but not unusually hot, hydrocarbon fires. [71] As Eagar said, "The temperature of the fire at the WTC was not unusual, and it was most definitely not capable of melting steel." [72] This led Eagar, FEMA and others to focus on what appeared to be the weakest point of the structures, namely, the points at which the floors were attached to the building frame. [73]

The large quantity of jet fuel carried by each aircraft ignited upon impact into each building. A significant portion of this fuel was consumed immediately in the ensuing fireballs. The remaining fuel is believed either to have flowed down through the buildings or to have burned off within a few minutes of the aircraft impact. The heat produced by this burning jet fuel does not by itself appear to have been sufficient to initiate the structural collapses. However, as the burning jet fuel spread across several floors of the buildings, it ignited much of the buildings’ contents, causing simultaneous fires across several floors of both buildings. The heat output from these fires is estimated to have been comparable to the power produced by a large commercial power generating station. Over a period of many minutes, this heat induced additional stresses into the damaged structural frames while simultaneously softening and weakening these frames. This additional loading and the resulting damage were sufficient to induce the collapse of both structures. [74]

NIST report

After the FEMA report had been published, and following pressure from technical experts, industry leaders and families of victims, the Commerce Department's National Institute of Standards and Technology conducted a three-year, $16 million investigation into the structural failure and progressive collapse of several WTC complex structures. [75] The study included in-house technical expertise, along with assistance from several outside private institutions, including the Structural Engineering Institute of the American Society of Civil Engineers, Society of Fire Protection Engineers, National Fire Protection Association, American Institute of Steel Construction, Simpson Gumpertz & Heger Inc., Council on Tall Buildings and Urban Habitat, and the Structural Engineers Association of New York.

The scope of the NIST investigation was focused on identifying "the sequence of events" that triggered the collapse, and did not include detailed analysis of the collapse mechanism itself (after the point at which events made the collapse inevitable). [76] [77] [78] In line with the concerns of most engineers, NIST focused on the airplane impacts and the spread and effects of the fires, modeling these using the software program Fire Dynamics Simulator. NIST developed several highly detailed structural models for specific sub-systems such as the floor trusses as well as a global model of the towers as a whole which is less detailed. These models are static or quasi-static, including deformation but not the motion of structural elements after rupture as would dynamic models. So, the NIST models are useful for determining how the collapse was triggered, but do not shed light on events after that point.

James Quintiere, professor of fire protection engineering at the University of Maryland, called the spoliation of the steel "a gross error" that NIST should have openly criticized. [79] He also noted that the report lacked a timeline and physical evidence to support its conclusions. [80] Some engineers have suggested that understanding of the collapse mechanism could be improved by developing an animated sequence of the collapses based on a global dynamic model, and comparing it with the video evidence of the actual collapses. [81] The NIST report for WTC 7 concluded that no blast sounds were heard on audio and video footage, or were reported by witnesses. [82]

7 World Trade Center

In May 2002, FEMA issued a report on the collapse based on a preliminary investigation conducted jointly with the Structural Engineering Institute of the American Society of Civil Engineers under leadership of Dr. W. Gene Corley, P.E. FEMA made preliminary findings that the collapse was not primarily caused by actual impact damage from the collapse of 1 WTC and 2 WTC but by fires on multiple stories ignited by debris from the other two towers that continued unabated due to lack of water for sprinklers or manual firefighting. The report did not reach conclusions about the cause of the collapse and called for further investigation. [ citação necessária ]

In response to FEMA's concerns, the National Institute of Standards and Technology (NIST) was authorized to lead an investigation into the structural failure and collapse of the World Trade Center twin towers and 7 World Trade Center. [83] The investigation, led by Dr S. Shyam Sunder, drew not only upon in-house technical expertise, but also upon the knowledge of several outside private institutions, including the Structural Engineering Institute of the American Society of Civil Engineers (SEI/ASCE), the Society of Fire Protection Engineers (SFPE), the National Fire Protection Association (NFPA), the American Institute of Steel Construction (AISC), the Council on Tall Buildings and Urban Habitat (CTBUH), and the Structural Engineers Association of New York (SEAoNY). [84]

The bulk of the investigation of 7 World Trade Center was delayed until after reports were completed on the collapse of the World Trade Center twin towers. [44] In the meantime, NIST provided a preliminary report about 7 World Trade Center in June 2004, and thereafter released occasional updates on the investigation. [37] According to NIST, the investigation of 7 World Trade Center was delayed for a number of reasons, including that NIST staff who had been working on 7 World Trade Center were assigned full-time from June 2004 to September 2005 to work on the investigation of the collapse of the twin towers. [13] In June 2007, Shyam Sunder explained, "We are proceeding as quickly as possible while rigorously testing and evaluating a wide range of scenarios to reach the most definitive conclusion possible. The 7 WTC investigation is in some respects just as challenging, if not more so, than the study of the towers. However, the current study does benefit greatly from the significant technological advances achieved and lessons learned from our work on the towers." [85]

In November 2008, NIST released its final report on the causes of the collapse of 7 World Trade Center. [38] This followed their August 21, 2008 draft report which included a period for public comments. [44] In its investigation, NIST utilized ANSYS to model events leading up to collapse initiation and LS-DYNA models to simulate the global response to the initiating events. [86] NIST determined that diesel fuel did not play an important role, nor did the structural damage from the collapse of the twin towers, nor did the transfer elements (trusses, girders, and cantilever overhangs), but the lack of water to fight the fire was an important factor. The fires burned out of control during the afternoon, causing floor beams near Column 79 to expand and push a key girder off its seat, triggering the floors to fail around column 79 on Floors 8 to 14. With a loss of lateral support across nine floors, Column 79 soon buckled – pulling the East penthouse and nearby columns down with it. With the buckling of these critical columns, the collapse then progressed east-to-west across the core, ultimately overloading the perimeter support, which buckled between Floors 7 and 17, causing the entire building above to fall downward as a single unit. From collapse timing measurements taken from a video of the north face of the building, NIST observed that the building's exterior facade fell at free fall acceleration through a distance of approximately 8 stories (32 meters, or 105 feet), noting "the collapse time was approximately 40 percent longer than that of free fall for the first 18 stories of descent." [87] The fires, fueled by office contents, along with the lack of water, were the key reasons for the collapse. [38]

The collapse of the old 7 World Trade Center is remarkable because it was the first known instance of a tall building collapsing primarily as a result of uncontrolled fires. [44] Based on its investigation, NIST reiterated several recommendations it had made in its earlier report on the collapse of the twin towers, and urged immediate action on a further recommendation: that fire resistance should be evaluated under the assumption that sprinklers are unavailable and that the effects of thermal expansion on floor support systems be considered. Recognizing that current building codes are drawn to prevent loss of life rather than building collapse, the main point of NIST's recommendations is that buildings should not collapse from fire even if sprinklers are unavailable. [38]

Other investigations

In 2003, Asif Usmani, Professor of Structural Engineering at University of Edinburgh, published a paper with two colleagues. They provisionally concluded the fires alone, without any damage from the airplanes, could have been enough to bring down the buildings. In their view, the towers were uniquely vulnerable to the effects of large fires on several floors at the same time. [88] When the NIST report was published, Barbara Lane, with the UK engineering firm Arup, criticized its conclusion that the loss of fire proofing was a necessary factor in causing the collapses "We have carried out computer simulations which show that the towers would have collapsed after a major fire on three floors at once, even with fireproofing in place and without any damage from plane impact." [89] Jose L. Torero, formerly of the BRE Centre for Fire Safety Engineering at the University of Edinburgh, pursued further research into the potentially catastrophic effects of fire on real-scale buildings. [90] [91] [92]

Cleanup

The cleanup was a massive operation coordinated by the City of New York Department of Design and Construction. On September 22, a preliminary cleanup plan was delivered by Controlled Demolition, Inc. (CDI) of Phoenix, Maryland. [93] Costing hundreds of millions of dollars, it involved round-the-clock operations with many contractors and subcontractors. [94] By early November, with a third of the debris removed, officials began to reduce the number of firefighters and police officers assigned to recovering the remains of victims, in order to prioritize the removal of debris. This caused confrontations with firefighters. [95] Despite efforts to extinguish the blaze, the large pile of debris burned for three months, until the majority of the rubble was finally removed from the site. [96] [97] In 2007, the demolition of the surrounding damaged buildings was still ongoing as new construction proceeded on the World Trade Center's replacement, 1 World Trade Center.

Efeitos na saúde

The collapse of the World Trade Center produced enormous clouds of dust that covered Manhattan for days. On September 18, 2001, the United States Environmental Protection Agency (EPA) assured the public that the air in Manhattan was "safe to breathe". [98] In 2003 the EPA's inspector general found that the agency did not at that time have sufficient data to make such a statement. Dust from the collapse seriously reduced air quality and is likely the cause of many respiratory illnesses in lower Manhattan. Asbestosis is such an illness, and asbestos would have been present in the dust. [99] Significant long term medical and psychological effects have been found among first responders including elevated levels of asthma, sinusitis, gastroesophageal reflux disease and posttraumatic stress disorder. [100]

Health effects also extended to residents, students, and office workers of Lower Manhattan and nearby Chinatown. [101] Several deaths have been linked to the toxic dust, and the victims' names will be included in the World Trade Center memorial. [102] More than 18,000 people have suffered from illnesses from the dust. [103]


Join Our Members List For Exclusive Reports

From numerous camera angles, what we see here is the collapse of the North Tower of the World Trade Center on 9/11. You will notice a remnant spire from the structural steel, which remains standing for a few moments after the bulk of the Tower’s collapse.

Then, as if Tinker Bell were hovering over there waving her magic wand, the spire literally turns into Fairy Dust before your eyes. You don’t have to believe me. Just watch it. From several angles.

The term “Dustification” was coined by Dr Judy Wood among others, like “Toasted Cars” to describe the anomalous evidence at the 9/11 crime scene, for which she felt normal descriptors were inadequate. The evidence was hauled off to the Fresh Kills dump in Staten Island without a proper crime scene investigation and the burnt steel was sold on the Chinese market at breakneck speed, all of this possibly to deter discovery of the “molecular dissociation” Dr Wood conjectured had been caused by Directed Energy Weapons that dustified the towers and toasted the cars. Wood’s exotic hypothesis might make more sense than the even kookier official explanations but we don’t really know what happened.

Still, I want you to see the image of this dustifying spire in your mind’s eye the next time someone speaks to you with authority about something they read in O jornal New York Times ou The Washington Post or about what they saw on CNN, NBC, ABC, CBS, BBC, etc.

I want you to see the image of this dustifying spire when you recall that this is the same Mainstream Media that told you that airliners caused the collapse of the World Trade Center Towers, when expert pilots say they could not have maneuvered Jumbo Jets to nail their targets so perfectly, let alone to fly at full speed at such low altitudes due to higher-density air, let alone with delicate aluminum airframes that could not penetrate the structural steel of the World Trade Center Towers, let alone that the kerosene jet fuel could not burn hot enough to melt that structural steel, let alone that NORAD stood down on the very day that the very thing they were created for and had been training daily since 1960 to defend against – happened.

I want you to see the image of this dustifying spire when you recall that this is the same Mainstream Media that lied us into war with Iraq and Afghanistan, killing an estimated 1 million innocent people. The Shadow Government people who presided over all of the above and who covered it up not only walk free and are multi-millionaires but many still have jobs in the Government – and guess what? Donald Trump is not one of them.

I want you to see the image of this dustifying spire when you recall that this is the same Mainstream Media that is shrieking to you every day that Donald Trump is worse than George W Bush and that Trump needs to be impeached.


New Tapes Reveal 9/11 Drama

In gripping, vivid accounts of individual heroism and organizational chaos, firefighters describe their response to - and escape from - the World Trade Center in 12,000 pages of oral histories made public today.

The histories, recorded in the weeks after the September 11th attack, offer some of the most detailed and intimate descriptions of the day's horror as seen through the eyes of the firefighters who made the iconic rush into the twin towers, and lost three hundred and forty-three of their brethren.

Compelled by a lawsuit filed by The New York Times when the FDNY did not comply with a freedom of information request and ruling by New York's highest court, the department made public 15 hours of radio transmissions and more than 500 oral histories describing the rush to the World Trade Center, which saved an unknown number of civilians.

Some families and other critics of the city's response have been hoping the new documents would help them challenge the conclusion that many firefighters in the north tower heard, but chose to ignore, an evacuation message issued after the south tower collapsed at 9:59 a.m.

CBS News Correspondent Trish Regan reports that Michael Burke's brother, William, was the only firefighter in his company who didn't make it out of the north tower. Michael told Regan that he will listen to the tapes when he feels ready.

"I will probably listen to them in bits and pieces. I think they'll be very difficult. It will be interesting to hear if we could hear Billy's voice," he said.

Notícias populares

The New York court ruling allowed the FDNY to remove painful or embarrassing portions of the tapes before releasing them, CBS' Bianca Solorzano reports. Regardless knowing the statements could have been edited, at least 450 relatives of firefighters killed in the tower collapses have requested copies of the oral histories so to gain any previously shrouded information about their loved ones' last moments.

Independent investigations with access to the documents, including that of the New York Times, have already described major flaws in the city's response to the attack: Emergency radios did not function properly. Police and firefighters did not work together. Discipline broke down. Vital messages went unheard.

Listening to the tapes yields an array of emotions. Some voices are sad some are terse. Some of the audio is garbled or difficult to understand. Hear more audio.

The 945 minutes of dispatches and recorded histories fill 23 cds, WCBS' Marcia Kramer reports. A reading of just a few of the 12,000 pages of transcripts from the oral histories made clear they were packed with dramatic descriptions of the day.

"When the south tower collapsed, what we did was we either ran, got blown or fell down. . I realized . we have people up there," said Fire Chief Salvatore Cassano. "The building is loaded with our guys."

Cassano was manning the department's command post with Department Chief Peter Ganci, who was later killed after the two were separated. Ganci was the highest-ranking firefighter who died that day.

"I'd like to hear his voice again," one father of a fallen firefighter

Firefighter Kirk Long, whose Engine 1 was sent to the World Trade Center's north tower &mdash the first to be struck by a plane and the second to collapse &mdash described rushing up a stairway as evacuees were coming down.

"I was watching every person coming down, looked at their face, just to make them happy that they were getting out and we were going in, and everything was OK," Long said in his oral history.

Long said he heard the north tower shake and thought something in the basement had exploded.

"At that time I never knew that the south tower had gone down," he said.

Firefighter Long described leaving the north tower and being helped by another firefighter to another building nearby that had some clean air.

"There was a lot of mothers and babies there," he said. "I was ready to leave. They were a little shook up because I was covered up with all this dust. I was leaving and they started to cry. They didn't want me to go without them. So I stayed for maybe 10 or 15 minutes until it cleared up a little bit. Then I walked them over to the west side, where there were boats and fresh air."

At least 450 relatives of firefighters killed in the trade center collapse requested copies of the oral histories and radio recordings, and they received them by express mail Friday, the fire department said.

Another firefighter, Patrick Martin of Engine 229, said that after the south tower had collapsed and before the north tower came down, his lieutenant instructed him to go on a boat that was taking people to hospitals across the Hudson River.

"I told him I wasn't leaving," Martin said. "We were still missing one guy."

Fire Lt. Gregg Hansson, whose Engine 24 was called at 8:47 a.m. - one minute after the first plane crash &mdash described hearing the call to evacuate while he was on the 35th floor of the north tower.

"I was in the vicinity of the battalion chief, who was on the command channel, when I heard a mayday given over the command channel to evacuate the building," Hansson said in his oral history. "He started to tell everyone to evacuate, and I did also. I saw all the units get up, everybody got their gear, everybody started for the staircases to evacuate."

Firefighter Maureen McArdle Schulman recalled how somebody yelled something was falling. They thought it may have been desks coming out of the windows but realized it was people. They were jumping out of the windows of the top floors and hitting the ground.

She said she was sickened because she felt like she was intruding on a religious sacrament.

She turned around to look at a wall so not to witness their deaths but could still hear the sound of people crashing into the ground.

The New York Times, joined by families of Sept. 11 victims, sued the city in 2002 to release the records, which were collected by the Fire Department in the days after the collapse of the twin towers.

The city withheld them, claiming the release would violate firefighters' privacy and jeopardize the prosecution of Zacarias Moussaoui, who ultimately pleaded guilty to conspiring with the Sept. 11 hijackers.

In March, the state's highest court ordered the city to release the oral histories and radio transmissions but said the city could edit out potentially painful and embarrassing portions.

In another oral history, fire Lt. Howard Hahn described using his cell phone that day but said his fire department radio was barely functioning.

"I was able to get through, but the transmissions was very hard," Hahn said. It was very hard to control. You're basically doing your own show."

First published on August 12, 2005 / 9:07 PM

© 2005 CBS Interactive Inc. All Rights Reserved. Este material não pode ser publicado, transmitido, reescrito ou redistribuído. A Associated Press contribuiu para este relatório.


Their 9/11 Heroism Saved Them

Only 20 people who were still inside the Twin Towers when they collapsed made it out alive, including six New York City firefighters from Ladder Company 6 in the city's Chinatown section.

Three of them remembered the events of the day on The Early Show Monday for co-anchor Harry Smith, who was reporting from ground zero.

They explained how assisting an elderly woman who worked in the north tower of the World Trade Center happened to put them in the right place at a very wrong time: a section a stairway that survived as the tower crumbled.

Capt. Jay Jonas, who has since been promoted to battalion chief, and five other firefighters from Ladder 6 responded to the attacks at the trade center immediately, arriving minutes after the first plane hit.

As they entered the lobby of the north tower, the south tower was hit.

Carrying 100 pounds of gear, the group started climbing the stairs in the north tower to help.

Notícias populares

When they reached the 28th floor, the building shook, and Jonas ordered his men to evacuate.

On the 19th floor, they came across an older woman, Josephine Harris, who had walked down from the 73rd floor. She was exhausted, and not sure she could continue.

Bill Butler, now a lieutenant, the strongest man in the unit, put his arm around her and guided her.

But Harris was slow, and when they reached the fourth floor, she stopped, protesting she couldn't go on.

Capt. Jonas feared for his men, but they would never leave Harris behind.

Then the rumbling started, and the north tower collapsed all around them. Miraculously, the area of the stairway they were in, Stairway B, remained intact.

Hours later, with Mayday calls and major efforts from their fellow firefighters, the group was found and rescued.

Jonas told Smith on Monday that his men were in the stairs to begin with because the elevators were broken, and, "That's where people needed help, so that's where we hadda be."

Butler said carrying all that gear up all those steps was "a tough trek. We were running into a lot of people, some that were severely injured and burned, but they were being cared for so, while we wouldn't normally pass people who were injured, we had to that day for the people above that we had to get to."

When did they know it was time to get out?

"For us," firefighter Sal D'Agostino told Smith, "it was when the south tower had collapsed and the captain went over to the window and saw that the south tower was no longer there, and then he came over to us and told us it was time for us to evacuate."

When they came upon Harris, she was worn out and moving very slowly the men agreed.

"We made it to the fourth floor (with her) and she was so tired, she couldn't support her own weight anymore, and she fell to the ground and she was telling us to leave her," Jonas said. "We weren't gonna leave her."

"As (the building) came down," Butler added, "there was this tremendous roar, like the same shaking as when the south tower collapsed, but at the same time the roar &mdash I liken it to two trains coming in different directions &mdash and you're standing in between them."

But, said D'Agostino, the fact that Harris had to stop, and the firefighters stopped with them, saved all their lives: "That's the key to the whole thing, when she can't go anymore and she's telling us to stop (helping her), we stayed together, and we stuck with her and then a couple of seconds later, you could hear the floors pancaking one on top of the other."

What does the fifth anniversary of that day mean to Jonas?

"(Sept. 11 was) a very solemn day," he said, "but it was also a day that we saw the worst in people and also saw the best in people. We had a tremendous amount of courage and compassion and heroism shown that day. And sometimes that gets overshadowed by the grief. But these people were incredible heroes (even before) these buildings came down."


CBS to Broadcast Videotape Shot Inside Towers During Trade Center Attack

CBS announced yesterday that it would broadcast a two-hour documentary special on March 10 culled from the videotape footage shot inside the World Trade Center by two young French filmmakers during the terrorist attack on Sept. 11.

The network said that it had acquired the rights to the video shot by the two brothers, Jules and Gedeon Naudet, and would transform it, with the help of producers and editors at CBS News, into a broadcast dedicated to commemorating the six-month anniversary of the attack. The tape has never been seen on television.

Leslie Moonves, the president of CBS Television, who made the deal for the network, called the footage ''just phenomenal material.'' The Naudets, who had been making a film about a firefighter recruit's early days on the job, were in a unique position to capture the events of that day from inside the trade center towers as firefighters struggled to contain the disaster. Jules Naudet was inside the north tower when the south tower collapsed.

Only a 10-second clip showing the first plane crashing into the north tower has previously been shown on television news broadcasts. A 90-minute version of the videotape was obtained by The New York Times, and a Jan. 12 front-page article detailed the gritty and horrifying scenes of firefighters and their commanders struggling to respond to the fires and the eventual collapse of the two buildings.

Some of the footage has also been shown to Fire Department officials and at some firehouses. About 90 firefighters who died that day have been identified on the tape, and the Naudets have made clips of those scenes available to their families.

Frank Gribbon, the spokesman for the Fire Department, praised the Naudets for ''the respectful way they have handled this.''

The Naudets, who are working closely with a firefighter friend, James Hanlon, insisted that the broadcast also serve a fund-raising purpose, and the CBS special will help promote the Uniformed Firefighters Association Scholarship Fund.

The Naudets will also direct part of the money that they are receiving for the film to the fund.

CBS acquired the tape through some unusual connections to Vanity Fair magazine, which is publishing an article about their experiences in the issue that comes out this week.

David Friend, a Vanity Fair editor who wrote the article, has been a friend of the Naudet family. He said yesterday that he contacted the brothers soon after the attack to interview them for an article after learning that they had been on the scene with videocameras.

Graydon Carter, the editor of Vanity Fair, then contacted Jim Wiatt of the William Morris talent agency as well as Mr. Moonves, both of whom are personal friends of his, to work out the arrangements for bringing the tape to television.

Mr. Wiatt called in another William Morris agent, Ben Silverman, to represent the Naudets and Mr. Hanlon directly. Mr. Wiatt said that all the William Morris fees on the CBS project would be donated to a fund designated by the Naudets.

Mr. Moonves did not disclose how much CBS had paid for the rights to the footage, but Mr. Silverman called it 'ɺ minimal fee.'' CBS did, however, commit resources to complete the film, including the services of Susan Zirinsky, the executive producer of the CBS news magazine program '❈ Hours.'' She is leading the creative team on the project, though she said the Naudets remained in control of the film. Mr. Carter and Mr. Friend are also executive producers.

Despite Ms. Zirinsky's participation, CBS emphasized that the special was not a product of CBS News. '�use of the fund-raising aspect, it does not fit under a news heading,'' Ms. Zirinsky said. Mr. Moonves said that it would not be an entertainment special either. ''We're not going to label it anything,'' he said.

The network will sell commercial time in the special, Mr. Moonves said, but ''we are looking for just two or three special sponsors.'' Mr. Carter said the deal mandated that commercials would run only at the beginning and end of the film, with one break in the middle.

Mr. Silverman predicted that the special would be one of the biggest events of the television season. ''I think 50 million will watch this,'' he said. He said that CBS had acquired two runs of the film, but that it would still be owned by the Naudets. He said that they might expand it later, and that it would be sold internationally next. Proceeds from that sale will also go to the scholarship fund.