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| == 9/11 and collapse == | |||
| {{See also|Collapse of the World Trade Center}} | |||
| ] | |||
| As the North Tower collapsed on September 11, 2001, heavy debris hit 7 World Trade Center, causing damage to the south face of the building.<ref name="NIST-june2004"/> Structural damage occurred to the southwest corner between Floors 7 and 17 and on the south face between Floor 44 and the roof; other possible structural damage includes a large vertical gash near the center of the south face between Floors 24 and 41.<ref name="ncstar1-a">{{cite book |url=http://wtc.nist.gov/NCSTAR1/PDF/NCSTAR%201A.pdf |format=PDF| publisher=NIST |title=NIST NCSTAR1-A: Final Report on the Collapse of World Trade Center Building 7 |month=November | year=2008 |accessdate=July 11, 2011}}</ref> The building was equipped with a ], 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 ] to deliver water. Also, water pressure was low, with little or no water to feed sprinklers.<ref>{{cite web |url=http://wtc.nist.gov/media/P4InvestigationofActiveFireProtection.pdf|format=PDF |title=Active Fire Protection Systems Issues |author=Grosshandler, William |publisher=NIST |accessdate=September 11, 2007}}</ref><ref>{{cite web |url=http://wtc.nist.gov/NCSTAR1/PDF/NCSTAR%201-4.pdf |format=PDF|title=Active Fire Protection Systems |author=Evans, David D |publisher=NIST |month=September | year=2005 |accessdate=August 26, 2010}}</ref> | |||
| After the North Tower collapsed, 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.<ref>{{cite web |url=http://graphics8.nytimes.com/packages/pdf/nyregion/20050812_WTC_GRAPHIC/9110313.PDF |format=PDF|title=Oral Histories From Sept. 11 – Interview with Captain Anthony Varriale |work=The New York Times |date=December 12, 2001 |accessdate=August 22, 2007}}</ref> 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.<ref>{{cite video | people=Spak, Steve | date=September 11, 2001 | url=http://video.google.com/videoplay?docid=6790722824543352916&hl=en | title=WTC 9-11-01 Day of Disaster | medium=Video | location=New York City | publisher=Spak, Steve}}</ref><ref>{{cite journal |author=Scheuerman, Arthur |url=http://wtc.nist.gov/media/ScheuermanStatementDec2006.pdf |format=PDF |title=The Collapse of Building 7 |date=December 8, 2006 |publisher=NIST |accessdate=June 29, 2007}}</ref> During the afternoon, fire was also seen on floors 6–10, 13–14, 19–22, and 29–30.<ref name="NIST-june2004"/> In particular, the fires on floors 7 through 9 and 11 through 13 continued to burn out of control during the afternoon.<ref name="nist-questions">{{cite web |url=http://www.nist.gov/public_affairs/factsheet/wtc_qa_082108.cfm |title=Questions and Answers about the NIST WTC 7 Investigation |publisher=NIST |accessdate=August 26, 2010}}</ref> 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 collapse.<ref name="hayden">{{cite web |url=http://www.firehouse.com/stateprovince/new-york/deputy-chief-peter-hayden |title=WTC: This Is Their Story, Interview with Chief Peter Hayden |publisher=Firehouse.com |date=September 9, 2002 |accessdate=March 3, 2011}}</ref> During the afternoon, firefighters also heard creaking sounds coming from the building.<ref>{{cite web |url=http://www.firehouse.com/stateprovince/new-york/captain-chris-boyle |title=WTC: This Is Their Story, Interview with Captain Chris Boyle |publisher=Firehouse.com |month=August | year=2002 |accessdate=March 3, 2011}}</ref> Around 3:30 pm FDNY Chief Daniel 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.<ref>{{cite news |url=http://www.nytimes.com/packages/html/nyregion/20050812_WTC_GRAPHIC/Nigro_Daniel.txt |title=Oral Histories From Sept. 11 – Interview with Chief Daniel Nigro |work=The New York Times |date=October 24, 2001 |accessdate=June 28, 2007}}</ref> 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.<ref name="fema-ch5"/><ref>{{cite video |url=http://www.archive.org/details/cbs200109111651-1733 |people=CBS News |date=September 11, 2001 |title=CBS Sept. 11, 2001 4:51 pm – 5:33 pm (September 11, 2001) |publisher=], CBS 9, Washington, D.C |medium=Television}} – View of the collapse captured by CBS</ref> There were no ] associated with the collapse. | |||
| In May 2002, the ] (FEMA) issued a report on the collapse based on a preliminary investigation conducted jointly with the Structural Engineering Institute of the ] under leadership of Dr. ], 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.<ref name="NIST Advisory Committee Dec 2007"/> | |||
| ] | |||
| In response to FEMA's concerns, the ] (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.<ref>{{cite web |url=http://www.nist.gov/public_affairs/factsheet/safety.cfm |title=NIST’s World Trade Center Investigation |publisher=NIST |accessdate=August 26, 2010}}</ref> 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 ] (SEI/ASCE), the ] (SFPE), the ] (NFPA), the American Institute of Steel Construction (AISC), the ] (CTBUH), and the ] (SEAoNY).<ref name="NIST-WTCreport">{{cite web |url=http://wtc.nist.gov/NCSTAR1/PDF/NCSTAR%201.pdf |format=PDF|title=Final Report on the Collapse of the World Trade Center Towers |publisher=National Institute of Standards and Technology (NIST) |month=September | year=2005 |accessdate=August 26, 2010}}</ref> | |||
| The bulk of the investigation of 7 World Trade Center was delayed until after reports were completed on the ] twin towers.<ref name="nist-questions"/> In the meantime, NIST provided a preliminary report about 7 World Trade Center in June 2004, and after that released occasional updates on the investigation.<ref name="NIST-june2004"/> 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.<ref name="NISTFAQ">{{cite web |url=http://wtc.nist.gov/pubs/factsheets/faqs_8_2006.htm |title=Answers to Frequently Asked Questions |publisher=National Institute of Standards and Technology |month=August | year=2006|accessdate=February 17, 2008}}</ref> 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."<ref name="NIST7STAT1">{{cite press release |url=http://www.nist.gov/public_affairs/releases/wtc_062907.cfm|title=NIST Status Update on World Trade Center 7 Investigation|last=Newman|first=Michael|date=June 29, 2007 |publisher=National Institute of Standards and Technology|accessdate=August 26, 2010}}</ref> | |||
| ] captured footage of the south face of 7 World Trade Center, including a glimpse of a gash, extending approximately 10 stories.]] | |||
| In November, 2008, NIST released its final report on the causes of the collapse of 7 World Trade Center.<ref name="ncstar1-a"/> This followed their August 21, 2008 draft report which included a period for public comments.<ref name="nist-questions"/> In its investigation, NIST utilized ] to model events leading up to collapse initiation and ] models to simulate the global response to the initiating events.<ref>{{cite web |url=http://wtc.nist.gov/media/WTC7_Approach_Summary12Dec06.pdf |format=PDF|title=WTC 7 Technical Approach and Status Summary |author=McAllister, Therese |publisher=NIST |date=December 12, 2006|accessdate=February 17, 2008}}</ref> 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. The fires, fueled by office contents, along with the lack of water, were the key reasons for the collapse.<ref name="ncstar1-a"/> | |||
| ]'s ] was heavily damaged from the collapse of 7 World Trade Center, and deconstruction was completed in the fall of 2009.]] | |||
| When the first 7 World Trade Center collapsed, debris caused substantial damage and contamination to the ]'s ] building, located adjacent at 30 West Broadway, to the extent that the building was not salvageable. In August 2007, Fiterman Hall was scheduled for deconstruction.<ref>{{cite web |url=http://www.lowermanhattan.info/construction/project_updates/fiterman_hall_39764.aspx |title=Fiterman Hall — Project Updates |publisher=Lower Manhattan Construction Command Center/LMDC |accessdate=August 23, 2007}}</ref> A revised plan called for demolition in 2009 and completion of the new Fiterman Hall in 2012, at a cost of $325 million.<ref> BMCC News, November 17, 2008</ref><ref>Agovino T Crain's New York Business November 13, 2008</ref> The adjacent ], an ] building constructed in 1926, had extensive damage to its east facade from the collapse of 7 World Trade Center, though it was able to be restored at a cost of US$1.4 billion.<ref name="nyconstruction">{{cite web |url=http://newyork.construction.com/projects/TopProjects04/Verizon.asp |title=Verizon Building Restoration |publisher=New York Construction (McGraw Hill) |accessdate=June 28, 2007}}</ref> | |||
| 7 World Trade Center housed SEC files relating to numerous Wall Street investigations, as well as other federal investigative files. All the files for approximately 3,000 to 4,000 SEC cases were destroyed. While some were backed up in other places, others were not, especially those classified as confidential.<ref name="NYL">{{cite news | title= SEC & EEOC: Attack Delays Investigations | date=September 17, 2001 | url =http://www.wanttoknow.info/010917natllawjournal.WTC7SECfiles | work=New York Lawyer | accessdate =July 9, 2008 }}</ref> Files relating Citigroup to the ] scandal were lost.<ref name="street">{{cite news | title=Citigroup Facing Subpoena in IPO Probe | url =http://www.thestreet.com/markets/matthewgoldstein/10036925.html | work=The Street | accessdate =July 9, 2008 }}</ref> The Equal Employment Opportunity Commission estimates over 10,000 cases will be affected.<ref name="NYLEq">{{cite news | title=Federal Agencies: Re-Creating Lost Files | date=September 14, 2001 | url =http://www.nylawyer.com/login.php?source=/news/01/09/091401b | work=New York Lawyer | accessdate =July 9, 2008 }}</ref> The Secret Service had its largest field office, with more than 200 employees, in WTC 7 and lost investigative files. Says one agent: “All the evidence that we stored at 7 World Trade, in all our cases, went down with the building.”<ref name="TTV">{{cite news | title=Ground Zero for the Secret Service | date=July 23, 2002 | url =http://www.g4tv.com/techtvvault/features/27904/Ground_Zero_for_the_Secret_Service.html | accessdate =July 9, 2008 }}</ref> | |||
| ===temporary break=== | |||
| 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.<ref name="nist-questions" /> 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.<ref name="ncstar1-a"> | |||
| ] say that the buildings that collapsed on September 11, including ], were felled by controlled demolition.<ref>{{cite news |url=http://www.usnews.com/usnews/news/articles/060903/11conspiracy.htm |title=Viewing 9/11 From a Grassy Knoll |author=Sullivan, Will |date=September 3, 2006|publisher=U.S. News & World Report|accessdate=February 17, 2008}}</ref><ref>{{cite news |title= The evolution of a conspiracy theory |url=http://news.bbc.co.uk/1/hi/magazine/7488159.stm |publisher=BBC News |date=July 4, 2008 |accessdate=July 4, 2008 }}</ref><ref>{{cite journal |last=Asquith |first=Christina |year=2006 |month=September |title=Conspiracies continue to abound surrounding 9/11: on the eve of the fifth anniversary, a group of professors say the attacks were an "inside job.". |journal=Diverse Issues in Higher Education |page=12 |url=http://findarticles.com/p/articles/mi_m0WMX/is_15_23/ai_n27000635 |accessdate=July 4, 2008 }}</ref><ref>{{cite web |url=http://www.popularmechanics.com/technology/military_law/1227842.html?page=5#wtc7 |title=WTC 7 Collapse |accessdate=July 9, 2008 |work=] |month=March | year=2005 }}</ref> The draft NIST report rejected this hypothesis, as the window breakages and blast sound that would have occurred if explosives were used were not observed.<ref>{{cite web |url=http://wtc.nist.gov/media/NIST_NCSTAR_1A_for_public_comment.pdf |title=Final Report on the Collapse of World Trade Center Building 7 – Draft for Public Comment |publisher=NIST |pages=22–3|month=August | year=2008 |format=PDF}}</ref> | |||
| The use of ] instead of explosives is discarded by NIST on the basis that it is unlikely the necessary 100 pounds of thermate for each steel column could have been planted without being discovered.<ref name="nist-questions" /> | |||
| Citations defined elsewhere:<ref name="NIST-june2004">{{cite web |year = 2004 |url = http://wtc.nist.gov/progress_report_june04/appendixl.pdf | format = PDF | title = Interim Report on WTC 7 | work=Appendix L | publisher=National Institute of Standards and Technology |accessdate =August 20, 2007}}</ref><ref name="fema-ch5">{{cite book |author=Gilsanz, Ramon, Edward M. DePaola, Christopher Marrion, and Harold "Bud" Nelson |url=http://www.fema.gov/pdf/library/fema403_ch5.pdf |format=PDF| publisher=FEMA |title=World Trade Center Building Performance Study |chapter=WTC7 (Chapter 5) |month=May | year=2002 |accessdate=February 17, 2008}}</ref><ref name="NIST Advisory Committee Dec 2007">{{cite web | url=http://wtc.nist.gov/media/NCSTACMeetingMinutes121807.pdf | title=Transcript: Meeting of the National Construction Safety Team Advisory Committee, December 18, 2007 | author=National Construction Safety Team Advisory Committee|format=PDF}}</ref> | |||
| <references/> | |||