September 11 attacks Warning: You are not logged in. Your IP address will be publicly visible if you make any edits. If you log in or create an account, your edits will be attributed to your username, along with other benefits.Anti-spam check. Do not fill this in! == Investigations == === FBI === {{further|Hijackers in the September 11 attacks}} Immediately after the attacks, the [[Federal Bureau of Investigation]] started [[PENTTBOM]], the largest criminal inquiry in United States history. At its height, more than half of the FBI's agents worked on the investigation and followed a half-million leads.<ref name='Pentbomb'>{{cite web |url=https://www.fbi.gov/about-us/history/famous-cases/9-11-investigation/9-11-investigation |archive-url=https://web.archive.org/web/20101010030053/http://www.fbi.gov/about-us/history/famous-cases/9-11-investigation/9-11-investigation |url-status=dead |archive-date=October 10, 2010 |title=9/11 Investigation (PENTTBOM) |access-date=April 11, 2012 |publisher=[[Federal Bureau of Investigation]]}}</ref> The FBI concluded that there was "clear and irrefutable" evidence linking Al-Qaeda and bin Laden to the attacks.<ref>{{cite web|title=Testimony of Dale L. Watson, Executive Assistant Director, Counterterrorism/Counterintelligence Division, FBI Before the Senate Select Committee on Intelligence|date=February 6, 2002|url=https://www.fbi.gov/congress/congress02/watson020602.htm |publisher=[[Federal Bureau of Investigation]]|access-date=September 4, 2011 |archive-url=https://web.archive.org/web/20100410013616/http://www.fbi.gov/congress/congress02/watson020602.htm |archive-date=April 10, 2010 |url-status=dead}}</ref> [[File:Mohamed Atta.jpg|thumb|upright|alt=Mohamed Atta headshot, expressionless, full face |[[Mohamed Atta]] was one of the main planners of the attacks and the operational leader, responsible for crashing Flight 11 into the North Tower]] The FBI quickly identified the hijackers, including leader Mohamed Atta, when his luggage was discovered at Boston's Logan Airport. Atta had been forced to check two of his three bags due to space limitations on the 19-seat commuter flight he took to Boston. Due to a new policy instituted to prevent flight delays, the luggage failed to make it aboard American Airlines Flight 11 as planned. The luggage contained the hijackers' names, assignments, and Al-Qaeda connections. "It had all these Arab-language{{sic}} papers that amounted to the Rosetta stone of the investigation", said one FBI agent.<ref name="Unraveling 9-11 Was in the Bags">{{cite news |title=Unraveling 9β11 Was in the Bags |date=February 6, 2009 |url=http://www.securityinfowatch.com/news/10555883/unraveling-9-11-was-in-the-bags |work=Newsday |access-date=April 11, 2012}}</ref> Within hours of the attacks, the FBI released the names and in many cases the personal details of the suspected pilots and hijackers.{{sfnp|Clarke|2004|pp=13β14}}<ref name="FBI 19">{{cite web |title=FBI Announces List of 19 Hijackers |publisher=Federal Bureau of Investigation |url=https://www.fbi.gov/news/pressrel/press-releases/fbi-announces-list-of-19-hijackers |access-date=September 4, 2011}}</ref> Abu Jandal, who served as bin Laden's chief bodyguard for years, confirmed the identity of seven hijackers as Al-Qaeda members during interrogations with the FBI on September 17. He had been jailed in a Yemeni prison since 2000.<ref>{{cite book |last=Bergen |first=Peter |author-link=Peter Bergen |date=2012 |title=Manhunt: The Ten-Year Search for Bin Laden β from 9/11 to Abbottabad |url=https://books.google.com/books?id=U7SriggSMckC&pg=PA29 |location=New York |publisher=Broadway Paperbacks |isbn=978-0-307-95588-3 |pages=29β30}}</ref><ref>{{cite book |last1=Soufan |first1=Ali |author-link1=Ali Soufan |last2=Freedman |first2=Daniel |date=2020 |title=The Black Banners (Declassified): How Torture Derailed the War on Terror after 9/11 |url=https://books.google.com/books?id=1tTXDwAAQBAJ&pg=PT302 |location=New York |publisher=W. W. Norton & Company |isbn=978-0-393-54072-7 |pages=317β318}}</ref> On September 27, 2001, photos of all 19 hijackers were released, along with information about possible nationalities and aliases.<ref>{{cite web|title=The FBI Releases 19 Photographs of Individuals Believed to be the Hijackers of the Four Airliners that Crashed on September 11, 2001|url=https://www.fbi.gov/news/pressrel/press-releases/the-fbi-releases-19-photographs-of-individuals-believed-to-be-the-hijackers|publisher=Federal Bureau of Investigation|access-date=September 4, 2011}}</ref> Fifteen of the men were from Saudi Arabia, two were from the [[United Arab Emirates]], one was from Egypt, and one was from Lebanon.<ref>{{cite news |last=Johnston |first=David|title=Two Years Later: 9/11 Tactics; Official Says Qaeda Recruited Saudi Hijackers to Strain Ties|url=https://www.nytimes.com/2003/09/09/us/two-years-later-9-11-tactics-official-says-qaeda-recruited-saudi-hijackers.html|access-date=September 4, 2011 |newspaper=The New York Times|date=September 9, 2003}}</ref> By midday, the U.S. National Security Agency and German intelligence agencies had intercepted communications pointing to Osama bin Laden.<ref>{{cite news |title=Piece by piece, the jigsaw of terror revealed |url=https://www.independent.co.uk/news/world/americas/piece-by-piece-the-jigsaw-of-terror-revealed-671334.html|archive-url=https://web.archive.org/web/20091015065134/http://www.independent.co.uk/news/world/americas/piece-by-piece-the-jigsaw-of-terror-revealed-671334.html|archive-date=October 15, 2009|access-date=September 4, 2011 |newspaper=The Independent|date=September 30, 2001 |location=London}}</ref> Two of the hijackers were known to have traveled with a bin Laden associate to Malaysia in 2000<ref>[http://avalon.law.yale.edu/sept11/911Report.pdf ''9/11 Commission Report''] pp. 266β72</ref> and hijacker [[Mohamed Atta]] had previously gone to Afghanistan.<ref>[https://web.archive.org/web/20121109021924/http://www.time.com/time/magazine/article/0%2C9171%2C1000987-2%2C00.html The Manhunt Goes Global] Time magazine October 15, 2001</ref> He and others were part of a terrorist cell in [[Hamburg]].<ref>{{cite news |first1=John |last1=Tagliabue |last2=Bonner |first2=Raymond |url=https://www.nytimes.com/2001/09/29/world/nation-challenged-german-intelligence-german-data-led-us-search-for-more-suicide.html|title=A Nation challenged: German Intelligence; German Data Led U.S. to Search For More Suicide Hijacker Teams |work=The New York Times |date=September 29, 2001 |access-date=September 4, 2011}}</ref> One of the members of the [[Hamburg cell]] in Germany was discovered to have been in communication with [[Khalid Sheikh Mohammed]] who was identified as a member of [[Al-Qaeda]].<ref>[http://avalon.law.yale.edu/sept11/911Report.pdf ''9/11 Commission Report''] pp. 276β77</ref> Authorities in the United States and the United Kingdom also obtained electronic intercepts, including telephone conversations and electronic bank transfers, which indicated that [[Mohammed Atef]], a bin Laden deputy, was a key figure in the planning of the 9/11 attacks. Intercepts were also obtained that revealed conversations that took place days before September 11 between bin Laden and an associate in Pakistan. In those conversations, the two referred to "an incident that would take place in America on, or around, September 11" and they discussed potential repercussions. In another conversation with an associate in Afghanistan, bin Laden discussed the "scale and effects of a forthcoming operation". These conversations did not specifically mention the World Trade Center, the Pentagon, or other specifics.<ref>{{cite news |title=The proof they did not reveal |work=Sunday Times |date=October 7, 2001|url=http://www.sunday-times.co.uk/news/pages/sti/2001/10/07/stiusausa02012.html|archive-url=https://web.archive.org/web/20011116020322/http://www.sunday-times.co.uk/news/pages/sti/2001/10/07/stiusausa02012.html|archive-date=November 16, 2001}}</ref> {{anchor|Origins}}{{Bar chart | title = Origins of [[Hijackers in the September 11 attacks|the 19 hijackers]] | label_type = Nationality | data_type = Number | bar_width = 20 | width_units = em | data_max = 19 | label1 = [[Saudi Arabia]] | data1 = 15 | label2 = [[United Arab Emirates]] | data2 = 2 | label3 = [[Egypt]] | data3 = 1 | label4 = [[Lebanon]] | data4 = 1 }} In their annual violent crime index for the year 2001, the FBI recorded the deaths from the attacks as murder, in separate tables so as not to mix them with other reported crimes for that year.<ref>{{Cite web |date=October 28, 2002 |title=Crime in the United States 2001, Section V |url=https://ojjdp.ojp.gov/ojstatbb/ezacjrp/pdf/cius_911.pdf |access-date=April 13, 2023 |publisher=[[Federal Bureau of Investigation]]}}</ref> In a disclaimer, the FBI stated that "the number of deaths is so great that combining it with the traditional [[crime statistics]] will have an [[outlier]] effect that falsely [[skewness|skews]] all types of measurements in the program's analyses".<ref>{{cite web|url=https://ucr.fbi.gov/crime-in-the-u.s/2001/toc01.pdf|title=Crime in the United States 2001|publisher=[[Federal Bureau of Investigation]]|date=October 28, 2002|page=2|access-date=September 12, 2018}}</ref> New York City also did not include the deaths in their annual crime statistics for 2001.<ref name="HuffPost story">{{cite news|last=Hanrahan|first=Mark|title=Henryk Siwiak, Shot To Death On September 11th: Case Remains Unsolved|url=http://www.huffingtonpost.com/2011/09/08/911-only-homicide-unsolved_n_953864.html|newspaper=[[Huffington Post]]|date=September 8, 2011|access-date=September 6, 2016}}</ref> === CIA === {{Further|September 11 intelligence before the attacks}} In 2004, [[John L. Helgerson]], the Inspector General of the [[Central Intelligence Agency]] (CIA), conducted an internal review of the agency's pre-9/11 performance and was harshly critical of senior CIA officials for not doing everything possible to confront terrorism.<ref name="Spiegel 2009">{{cite news |title=Ex-CIA Inspector General on Interrogation Report: 'The Agency Went over Bounds and Outside the Rules' |website=Der Spiegel |date=August 31, 2009 |url=https://www.spiegel.de/international/world/ex-cia-inspector-general-on-interrogation-report-the-agency-went-over-bounds-and-outside-the-rules-a-646010.html |access-date=February 3, 2021}}</ref> According to [[Philip Giraldi]] in ''[[The American Conservative]]'', Helgerson criticized their failure to stop two of the 9/11 hijackers, Nawaf al-Hazmi and Khalid al-Mihdhar, as they entered the United States and their failure to share information on the two men with the FBI.<ref>{{cite magazine |url=http://www.theamericanconservative.com/articles/deep-background/|title=Deep Background |magazine=American Conservative |date=April 1, 2005 |access-date=April 11, 2012}}</ref> In May 2007, senators from both major U.S. political parties (the [[Republican Party (United States)|Republican]] and [[Democratic Party (United States)|Democratic]] party) drafted legislation to make the review public. One of the backers, Senator [[Ron Wyden]] said, "The American people have a right to know what the Central Intelligence Agency was doing in those critical months before 9/11".<ref>{{cite news|first=Katherine |last=Shrader |title=Senators Want CIA to Release 9/11 Report |url=http://www.sfgate.com/cgi-bin/article.cgi?f=/n/a/2007/05/17/national/w131436D49.DTL |work=San Francisco Chronicle |agency=Associated Press |date=May 17, 2007 |access-date=September 4, 2011 |archive-url=https://web.archive.org/web/20071017005618/http://www.sfgate.com/cgi-bin/article.cgi?f=%2Fn%2Fa%2F2007%2F05%2F17%2Fnational%2Fw131436D49.DTL |archive-date=October 17, 2007 |url-status=dead}}</ref> The report was released in 2009 by President [[Barack Obama]].<ref name="Spiegel 2009" /> === Congressional inquiry === {{Main|Joint Inquiry into Intelligence Community Activities before and after the Terrorist Attacks of September 11, 2001}} In February 2002, the [[Senate Select Committee on Intelligence]] and the [[House Permanent Select Committee on Intelligence]] formed a joint inquiry into the performance of the [[U.S. Intelligence Community]].<ref>[http://www.intelligence.senate.gov/press/record.cfm?id=263577 Press Release of Intelligence Committee], Senate and House Intelligence Committees Announce Joint Inquiry into the September 11 Terrorist Attacks, February 14, 2002.</ref> Their 832-page report released in December 2002<ref>{{cite web|url=http://www.gpoaccess.gov/serialset/creports/911.html |title=Congressional Reports: Joint Inquiry into Intelligence Community Activities before and after the Terrorist Attacks of September 11, 2001 |access-date=August 10, 2010 |url-status=dead |archive-url=https://web.archive.org/web/20100807204747/http://www.gpoaccess.gov//serialset/creports/911.html |archive-date=August 7, 2010}}</ref> detailed failings of the FBI and CIA to use available information, including about terrorists the CIA knew were in the United States, to disrupt the plots.<ref name="Theoharis 2006 p222β224">{{cite book |editor-first=Athan G. |editor-last=Theoharis |title=The Central Intelligence Agency: Security Under Scrutiny |publisher=[[Greenwood Publishing Group]] |pages=[https://books.google.com/books?id=-nj4RLdHCU0C&pg=PA223 222β224] |year=2006 |isbn=0-313-33282-7}}</ref> The joint inquiry developed its information about possible involvement of Saudi Arabian government officials from non-classified sources.<ref name="McClatchy DC 2013-08-12">{{cite news |first=Ali |last=Watkins |url=http://www.mcclatchydc.com/2013/08/12/199122_senate-intelligence-panel-could.html?rh=1 |title=Senate intelligence panel could seek to declassify documents; it just doesn't |archive-url=https://web.archive.org/web/20140903123631/http://www.mcclatchydc.com/2013/08/12/199122_senate-intelligence-panel-could.html|archive-date=September 3, 2014 |publisher=[[The McClatchy Company|McClatchy Washington Bureau]] |date=August 12, 2013}}</ref> Nevertheless, the Bush administration demanded 28 related pages remain classified.<ref name="Theoharis 2006 p222β224" /> In December 2002, the inquiry's chair [[Bob Graham]] (D-FL) revealed in an interview that there was "evidence that there were foreign governments involved in facilitating the activities of at least some of the terrorists in the United States".<ref>[https://www.pbs.org/newshour/bb/politics-july-dec02-intelligence_12-11/ Improving Intelligence], [[PBS]] interview with Sen. Bob Graham, December 11, 2002.</ref> September 11 victim families were frustrated by the unanswered questions and redacted material from the congressional inquiry and demanded an independent commission.<ref name="Theoharis 2006 p222β224" /> September 11 victim families,<ref>{{cite news |first=Chris |last=Mondics |url=http://articles.philly.com/2014-03-31/business/48708504_1_osama-president-obama-law-firm |title=Struggling to detail alleged Saudi role in 9/11 attacks |work=[[Philadelphia Inquirer]] |date=March 31, 2014}}</ref> members of Congress<ref>[https://jones.house.gov/sites/jones.house.gov/files/Reps.%20Jones%20and%20Lynch%20Letter%20to%20Obama_28%20Pages.pdf April 10, 2014 Letter to Barack Obama] {{Webarchive|url=https://web.archive.org/web/20160907084340/http://jones.house.gov/sites/jones.house.gov/files/Reps.%20Jones%20and%20Lynch%20Letter%20to%20Obama_28%20Pages.pdf |date=September 7, 2016 }}, signed by Representatives [[Walter B. Jones Jr.]] and [[Stephen Lynch (politician)|Stephen Lynch]].</ref> and the Saudi Arabian government are still seeking the release of the documents.<ref>{{cite news |first=Jake |last=Tapper |author-link=Jake Tapper |url=http://thelead.blogs.cnn.com/2014/09/08/why-hasnt-obama-kept-promise-to-declassify-28-pages-about-911 |title=Why hasn't Obama kept a promise to declassify 28 pages of a report about 9/11? |publisher=[[CNN]] |date=September 8, 2014 |access-date=September 12, 2014 |archive-date=August 3, 2021 |archive-url=https://web.archive.org/web/20210803143353/https://thelead.blogs.cnn.com/2014/09/08/why-hasnt-obama-kept-promise-to-declassify-28-pages-about-911/ |url-status=dead }}</ref><ref>{{cite magazine |title=The Twenty-Eight Pages |magazine=[[The New Yorker]] |first=Lawrence |last=Wright |url=http://www.newyorker.com/news/daily-comment/twenty-eight-pages |date=September 9, 2014 |access-date=August 30, 2019}}</ref> In June 2016, CIA chief [[John O. Brennan|John Brennan]] said that he believes 28 redacted pages of a congressional inquiry into 9/11 will soon be made public, and that they will prove that the government of Saudi Arabia had no involvement in the September 11 attacks.<ref>{{cite news |first=Euan |last=McKirdy |url=http://edition.cnn.com/2016/06/12/politics/cia-john-brennan-saudi-arabia-9-11/ |title=CIA chief: Missing report pages exonerate Saudi Arabia in 9/11 attacks |publisher=[[CNN]] |date=June 14, 2016}}</ref> In September 2016, Congress passed the [[Justice Against Sponsors of Terrorism Act]] that would allow relatives of victims of the September 11 attacks to sue [[Saudi Arabia]] for its government's [[Alleged Saudi government role in the September 11 attacks|alleged role in the attacks]].<ref>"[https://www.usatoday.com/story/news/politics/2016/09/23/obama-veto-terrorism-lawsuit-bill-setting-up-override-battle/90407496/ Why Obama doesn't want 9/11 families suing Saudi Arabia]". ''USA Today''. September 23, 2016.</ref><ref>"[http://www.nydailynews.com/news/world/saudi-arabia-warns-750b-response-9-11-liability-suit-article-1.2603675 Saudi Arabia threatens to pull $750B from U.S. economy if Congress allows them to be sued for 9/11 terror attacks]". ''Daily News'' (New York). April 16, 2016.</ref><ref>"[http://www.nydailynews.com/news/world/saudi-government-didn-fund-terrorists-obama-aide-article-1.2605678 Mayor de Blasio joins Democrats in calling on President Obama to go after Saudi Arabia on 9/11 ties]". ''Daily News'' (New York). April 19, 2016.</ref> ===9/11 Commission=== {{Main|9/11 Commission|9/11 Commission Report}} {{See also|Criticism of the 9/11 Commission}} [[File:911report cover HIGHRES.png|thumb|The cover of the ''[[9/11 Commission Report]]'', a 585-page report released in 2004, on events leading up to the September 11 attacks and steps recommended to avoid a future terrorist attack]] The National Commission on Terrorist Attacks Upon the United States, popularly known as the [[9/11 Commission]], chaired by [[Thomas Kean]], [[governor of New Jersey]] from 1982 to 1990,{{efn|Former Secretary of State [[Henry Kissinger]] was initially appointed to head the commission<ref>{{cite news|url=https://www.pbs.org/newshour/bb/terrorism/july-dec02/investigation_11-27.html|title=Investigating Sept. 11|publisher=PBS|work=NewsHour|date=November 27, 2002|access-date=January 21, 2009|url-status=dead|archive-url= https://web.archive.org/web/20090220061250/http://www.pbs.org/newshour/bb/terrorism/july-dec02/investigation_11-27.html|archive-date= February 20, 2009}}</ref> but resigned only weeks after being appointed, to avoid conflicts of interest.<ref>{{cite news|publisher=[[Cable News Network]]|url= http://archives.cnn.com/2002/ALLPOLITICS/12/13/kissinger.resigns/|title=Kissinger resigns as head of 9/11 commission |date=December 13, 2002|access-date=August 7, 2006|url-status=dead|archive-url= https://web.archive.org/web/20060427145915/http://archives.cnn.com/2002/ALLPOLITICS/12/13/kissinger.resigns/|archive-date=April 27, 2006}}</ref> Former U.S. Senator [[George J. Mitchell|George Mitchell]] was originally appointed as the vice chairman, but he stepped down on December 10, 2002, not wanting to sever ties to his law firm.<ref>{{cite news |url=http://archives.cnn.com/2002/ALLPOLITICS/12/11/mitchell.resigns/ |title=Mitchell quits 9/11 probe |date=December 10, 2002 |publisher=CNN |access-date=January 21, 2009| archive-url= https://web.archive.org/web/20090220082114/http://archives.cnn.com/2002/ALLPOLITICS/12/11/mitchell.resigns/| archive-date= February 20, 2009 | url-status= live}}</ref> On December 15, 2002, Bush appointed former [[New Jersey]] Governor [[Thomas Kean|Tom Kean]] to head the commission.<ref>{{cite news |url=http://archives.cnn.com/2002/ALLPOLITICS/12/16/commission.kean/ |title=Bush taps ex-New Jersey governor for 9/11 panel |date=December 16, 2002 |publisher=CNN |access-date=January 21, 2009| archive-url= https://web.archive.org/web/20090220082119/http://archives.cnn.com/2002/ALLPOLITICS/12/16/commission.kean/| archive-date= February 20, 2009 | url-status= live}}</ref>}} was formed in late 2002 to prepare a thorough account of the circumstances surrounding the attacks, including preparedness for and the immediate response to the attacks.<ref>{{cite web|url=http://govinfo.library.unt.edu/911/about/bio_kean.htm|title=National Commission on Terrorist Attacks Upon the United States|publisher=govinfo.library.unt.edu|access-date=September 4, 2011}}</ref> On July 22, 2004, the commission issued the ''[[9/11 Commission Report]]'', a 585-page report based on its investigations and interviews. The report detailed the events leading up to the September 11 attacks, concluding that they were carried out by [[Al-Qaeda]]. The commission also examined how security and intelligence agencies were inadequately coordinated to prevent the attacks. According to the report, "We believe the 9/11 attacks revealed four kinds of failures: in imagination, policy, capabilities, and management".<ref>{{cite web |title=Foresight-and Hindsight |url=http://www.9-11commission.gov/report/911Report_Ch11.htm |publisher=National Commission on Terrorist Attacks Upon the United States |access-date=September 4, 2011}}</ref> The commission made numerous recommendations on how to prevent future attacks, and in 2011 was dismayed that several of its recommendations had yet to be implemented.<ref>{{cite news |last=Bennett |first=Brian |title=Post-9/11 assessment sees major security gaps |url=http://articles.latimes.com/2011/aug/30/nation/la-na-911-report-card-20110831 |newspaper=Los Angeles Times |date=August 30, 2011 |access-date=September 4, 2011}}</ref> === National Institute of Standards and Technology === {{Main|NIST World Trade Center Disaster Investigation}} {{See also|7 World Trade Center#9/11 and collapse}} [[File:WTC-Wreckage-exterior shell of south tower.jpg|thumb|The exterior support columns from the lower level of the South Tower remained standing after the [[Collapse of the World Trade Center|building collapsed]]]] The U.S. [[National Institute of Standards and Technology]] (NIST) investigated the collapses of the Twin Towers and 7{{spaces}}WTC. The investigations examined why the buildings collapsed and what fire protection measures were in place, and evaluated how fire protection systems might be improved in future construction.<ref name="NISTInvest">{{cite press release |title=NIST's World Trade Center Investigation |publisher=National Institute of Standards and Technology |date=September 8, 2006 |url=https://www.nist.gov/news-events/news/2006/09/nists-world-trade-center-investigation |access-date=September 4, 2011}}</ref> The investigation into the collapse of 1{{spaces}}WTC and 2{{spaces}}WTC was concluded in October 2005 and that of 7{{spaces}}WTC was completed in August 2008.<ref name="NIST WTC 7 Investigation">{{cite press release |title=NIST WTC 7 Investigation Finds Building Fires Caused Collapse |date=August 21, 2008 |publisher=The National Institute of Standards and Technology |url=https://www.nist.gov/news-events/news/2008/08/nist-wtc-7-investigation-finds-building-fires-caused-collapse |access-date=September 4, 2011}}</ref> NIST found that the fireproofing on the Twin Towers' steel infrastructures was blown off by the initial impact of the planes and that had this not occurred, the towers likely would have remained standing.<ref name="NISTCollapse">{{cite book|author=National Construction Safety Team |chapter-url=https://www.nist.gov/customcf/get_pdf.cfm?pub_id=909017 |title=Final Report on the Collapse of the World Trade Center Towers |publisher=National Institute of Standards and Technology, United States Department of Commerce |chapter=Executive Summary |date=September 2005 |access-date=April 10, 2011 |chapter-format=PDF}}</ref> A 2007 study of the north tower's collapse published by researchers of [[Purdue University]] determined that since the plane's impact had stripped off much of the structure's thermal insulation, the heat from a typical office fire would have softened and weakened the exposed girders and columns enough to initiate the collapse regardless of the number of columns cut or damaged by the impact.<ref>{{cite journal|last1=Irfanoglu |first1=A.|last2=Hoffmann |first2=C. M.|doi=10.1061/(ASCE)0887-3828(2008)22:1(62)|title=Engineering Perspective of the Collapse of WTC-I|journal=Journal of Performance of Constructed Facilities|volume=22|page=62|year=2008|quote=As the aircraft debris went through several stories in the tower, much of the thermal insulation on the core columns would have been scoured off. Under such conditions, the ensuing fire would be sufficient to cause instability and initiate collapse. From an engineering perspective, impact damage to the core structure had a negligible effect on the critical thermal load required to initiate collapse in the core structure.}}</ref><ref>{{cite news|title=Purdue creates scientifically based animation of 9/11 attack|last=Tally|first=Steve|publisher=Purdue News Service|url=http://news.uns.purdue.edu/x/2007a/070612HoffmannWTC.html|date=June 12, 2007|access-date=September 4, 2011|quote=The aircraft moved through the building as if it were a hot and fast lava flow", Sozen says. "Consequently, much of the fireproofing insulation was ripped off the structure. Even if all of the columns and girders had survived the impact{{snd}}an unlikely event{{snd}}the structure would fail as the result of a buckling of the columns. The heat from an ordinary office fire would suffice to soften and weaken the unprotected steel. Evaluation of the effects of the fire on the core column structure, with the insulation removed by the impact, showed that collapse would follow whatever the number of columns cut at the time of the impact.|archive-date=December 31, 2018|archive-url=https://web.archive.org/web/20181231084252/https://news.uns.purdue.edu/x/2007a/070612HoffmannWTC.html|url-status=dead}}</ref> The director of the original investigation stated that "the towers did amazingly well. The terrorist aircraft didn't bring the buildings down; it was the fire that followed. It was proven that you could take out two-thirds of the columns in a tower and the building would still stand".<ref name="TerrorProof">{{cite web|title=Building a Terror-Proof Skyscraper: Experts Debate Feasibility, Options |first=Pete |last=Sigmund |url=http://www.constructionequipmentguide.com/Building-a-Terror-Proof-Skyscraper-Experts-Debate-Feasibility-Options/2598/ |access-date=April 11, 2012 |date=September 25, 2002}}</ref> The fires weakened the trusses supporting the floors, making the floors sag. The sagging floors pulled on the exterior steel columns causing the exterior columns to bow inward. With the damage to the core columns, the buckling exterior columns could no longer support the buildings, causing them to collapse. Additionally, the report found the towers' stairwells were not adequately reinforced to provide adequate [[Fire escape|emergency escape]] for people above the impact zones.<ref name="NIST">{{cite web|title=Translating WTC Recommendations into Model Building Codes|publisher=National Institute of Standards and Technology|url=http://wtc.nist.gov/NIBS_MMC/CodeChangeProposals.htm|archive-url=https://web.archive.org/web/20110310004023/http://wtc.nist.gov/NIBS_MMC/CodeChangeProposals.htm|archive-date=March 10, 2011|access-date=September 4, 2011 |date=October 25, 2007}}</ref> NIST concluded that uncontrolled fires in 7{{spaces}}WTC caused floor beams and girders to heat and subsequently "caused a critical support column to fail, initiating a fire-induced progressive collapse that brought the building down".<ref name="NIST WTC 7 Investigation" /> === Alleged Saudi government role === {{Main|Alleged Saudi government role in the September 11 attacks}}{{See also|Saudi ArabiaβUnited States relations|Saudi Arabia and state-sponsored terrorism|The 28 pages}} In July 2016, the Obama administration released a document compiled by U.S. investigators Dana Lesemann and Michael Jacobson, known as "File 17",<ref>{{cite news |title=Saudi diplomats 'links to 9/11 attackers' |url=https://www.thetimes.co.uk/article/saudi-diplomats-linked-to-9-11-plot-9hgrfjhbm |work=The Week |date=April 20, 2016}}</ref> which contains a list naming three dozen people, including the suspected [[General Intelligence Presidency|Saudi intelligence]] officers attached to Saudi Arabia's embassy in Washington, D.C.,<ref>{{cite news |title=US to reveal Saudi official allegedly tied to 9/11 attackers |url=https://www.aljazeera.com/news/2019/09/reveal-saudi-official-allegedly-tied-911-attackers-190913011926350.html |publisher=Al Jazeera |date=September 13, 2019}}</ref> which connects Saudi Arabia to the hijackers.<ref>{{cite news|last1=Riechmann|first1=Deb|title=File 17 Is Glimpse Into Still-Secret 28 Pages About 9/11|url=https://apnews.com/fe56c5d224a8463aa7cfc6ccf4689122 |publisher=Associated Press |date=July 2, 2016}}</ref><ref>{{cite news |title=CIA and Saudi Arabia Conspired to Keep 9/11 Details Secret, New Book Says |url=https://www.newsweek.com/cia-and-saudi-arabia-conspired-keep-911-details-secret-new-book-says-1091935 |work=Newsweek |date=August 28, 2018}}</ref> In September 2016, Congress passed the [[Justice Against Sponsors of Terrorism Act]].<ref name="Stempel">{{cite news|last=Stempel|first=Jonathan|date=March 28, 2018|title=Saudi Arabia must face U.S. lawsuits over Sept. 11 attacks|url=https://www.reuters.com/article/us-usa-saudi-sept11/saudi-arabia-must-face-u-s-lawsuits-over-sept-11-attacks-idUSKBN1H43A1|publisher=Reuters|access-date=November 22, 2018}}</ref><ref>{{cite news|first1=Scott|last1=Horsley|first2=Alisa|last2=Chang|title=Senate Votes To Override Obama's Veto On Sept. 11 Lawsuit Bill|publisher=NPR|url=https://www.npr.org/2016/09/28/495709481/sept-11-lawsuits-vote-today-could-be-first-reversal-of-an-obama-veto|date=September 28, 2016}}</ref> The practical effect of the legislation was to allow the continuation of a longstanding civil lawsuit brought by families of victims of the September 11 attacks against Saudi Arabia for its government's alleged role in the attacks.<ref>{{cite web|title=S.2040 β Justice Against Sponsors of Terrorism Act|url=https://www.congress.gov/bill/114th-congress/senate-bill/2040|publisher=U.S. Congress |access-date=May 20, 2016}}</ref> In March 2018, a U.S. judge formally allowed a suit to move forward against the government of Saudi Arabia brought by 9/11 survivors and victims' families.<ref name="Stempel" /> In 2022, the families of some 9/11 victims obtained two videos and a notepad seized from Saudi national [[Omar al-Bayoumi]] by the British courts. The first video showed him hosting a party in [[San Diego]] for Nawaf al-Hazmi and Khalid al-Mihdhar, the first two hijackers to arrive in the U.S. The other video showed al-Bayoumi greeting the cleric [[Anwar al-Awlaki]], who was blamed for radicalizing Americans and later killed in a CIA drone strike. The notepad depicted a hand-drawn aeroplane and some mathematical equations that, according to a pilot's court statement, might have been used to calculate the rate of descent to get to a target. According to a 2017 FBI memo, from the late 1990s up until the 9/11 attack, al-Bayoumi was a paid cooptee of the Saudi [[General Intelligence Presidency]]. {{As of|2022|04}} he is believed to be living in Saudi Arabia, which has denied any involvement in 9/11.<ref>{{cite news |last1=Herridge |first1=Catherine |title=Newly released video shows 9/11 hijackers with alleged Saudi intelligence operative |url=https://www.cbsnews.com/news/911-hijackers-video-saudi-intelligence-official-omar-al-bayoumi/ |publisher=CBS News |date=27 April 2022}}</ref> Summary: Please note that all contributions to Christianpedia may be edited, altered, or removed by other contributors. If you do not want your writing to be edited mercilessly, then do not submit it here. You are also promising us that you wrote this yourself, or copied it from a public domain or similar free resource (see Christianpedia:Copyrights for details). Do not submit copyrighted work without permission! 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