September 11 attacks
| September 11 attacks | |
|---|---|
| |
| Location | |
| Date | September 11, 2001 c. 8:13 a.m.[b] – 10:03 a.m.[c] (EDT) |
| Target |
|
Attack type | |
| Deaths | 2,996[d] (2,977 in the attacks plus the 19 hijackers) |
| Injured | 6,000–25,000+[e] |
| Perpetrators | Al-Qaeda led by Osama bin Laden The Hamburg cell (see also: responsibility) |
No. of participants | 19 |
| Motive | Several; see Motives for the September 11 attacks and fatwas of Osama bin Laden |
| Convicted | |
.JPEG)
.jpg)
.jpg)
| September 11 attacks |
|---|
 |
The September 11 attacks,[f] colloquially known as 9/11,[g] were a coordinated series of suicide attacks perpetrated by the Islamic terrorist organization al-Qaeda against the United States in 2001. 19 terrorists hijacked four airliners, then flew one into each of the Twin Towers at the World Trade Center in New York City. The third plane crashed into the Pentagon, the headquarters of the United States Department of Defense, in Arlington County, Virginia. The fourth plane crashed in a rural Pennsylvania field during a passenger revolt. In response to the attacks, the United States launched the global war on terror, seeking to eliminate hostile groups deemed terrorist organizations and the governments purported to support them. This foreign policy agenda was conducted over the next two decades.
The ringleader, Mohamed Atta, flew American Airlines Flight 11 into the North Tower of the World Trade Center complex at 8:46 a.m. At 9:03 a.m.[h] Marwan al-Shehhi flew United Airlines Flight 175 into the South Tower. Both collapsed within an hour and forty-two minutes,[i] destroying the remaining five structures in the complex. Hani Hanjour flew American Airlines Flight 77 into the Pentagon at 9:37 a.m., causing a partial collapse. United Airlines Flight 93, hijacked by Ziad Jarrah, was believed to target either the United States Capitol or the White House. Alerted to the previous attacks, the passengers revolted and the hijackers crashed the aircraft into a field near Shanksville, Pennsylvania, at 10:03 a.m. The Federal Aviation Administration ordered a ground stop for all traffic in U.S. airspace, requiring all airborne aircraft to return to their point of origin or divert to Canada. The actions undertaken in Canada to support incoming aircraft and their occupants were collectively titled Operation Yellow Ribbon.
That evening, the Central Intelligence Agency informed President George W. Bush that its Counterterrorism Center had identified the attacks as having been the work of al-Qaeda under Osama bin Laden. The United States responded by launching the war on terror and invading Afghanistan. NATO's invocation of Article 5 of the North Atlantic Treaty—its only usage to date—called upon allies to fight al-Qaeda as well. As U.S. and allied invasion forces swept through Afghanistan, bin Laden eluded them. He denied any involvement until 2004, when excerpts of a taped statement in which he accepted responsibility for the attacks were released. Al-Qaeda's cited motivations included U.S. support of Israel, the presence of U.S. military bases in Saudi Arabia, and sanctions against Iraq. The nearly decade-long manhunt for bin Laden concluded in May 2011, when he was killed during a U.S. military raid in Abbottabad, Pakistan. The war in Afghanistan continued for another decade.
The attacks killed 2,977 people, injured thousands more,[j] and gave rise to long-term health consequences while causing at least US$10 billion in infrastructure and property damage. It remains the deadliest terrorist attack in history, as well as the deadliest incident for firefighters and law enforcement personnel in American history, killing 343 and 72 members, respectively. The crashes of Flight 11 and Flight 175 were the deadliest aviation disasters of all time, and the collision of Flight 77 with the Pentagon resulted in the fourth-highest number of ground fatalities in a plane crash in history. The destruction of the World Trade Center and its environs seriously harmed the U.S. economy and induced global market shocks. Many other countries strengthened anti-terrorism legislation and expanded their powers of law enforcement and intelligence agencies. The total number of deaths caused by the attacks, combined with the death tolls from the conflicts they directly incited, has been estimated by the Costs of War Project to be more than 4.5 million.[17]
Cleanup of the World Trade Center site (colloquially known as "Ground Zero") was completed in May 2002, while the Pentagon was repaired within a year. After delays in the design of a replacement complex, six new buildings were planned to replace the lost towers at the World Trade Center site, along with a museum and memorial dedicated to those who were killed or injured in the attacks. The tallest building, One World Trade Center, began construction in 2006 and opened in 2014. Memorials to the attacks include the National September 11 Memorial & Museum in New York City; the Pentagon Memorial in Arlington County, Virginia; and the Flight 93 National Memorial at the Pennsylvania crash site.
Background
Osama bin Laden
In 1996, Osama bin Laden, by then a former Saudi Arabian citizen who led the jihadist organization al-Qaeda, issued his first fatwa, which declared jihad against the United States and demanded the expulsion of all American troops stationed in Arabia.[18] An adherent of Islam, bin Laden interpreted Muhammad as banning non-Muslims from Arabia.[19] He thus considered the U.S. troop presence a provocation to all Muslims.[20] Regarding his holy war, Bin-laden stated, "We do not differentiate between those dressed in military uniforms, and civilians; they are all targets of this fatwa."[18]
Bin Laden was living in Sudan prior to 1996, when the Sudanese government exiled him after Saudi and U.S. pressure.[21] Bin Laden returned to Afghanistan, which was run by the Taliban. They allowed al-Qaeda to use the country as its base of operations.[21][22] He then orchestrated the 9/11 attacks on the U.S. in 2001. He personally told his subordinate participants to target the World Trade Center in New York City and the Pentagon in Arlington, Virginia, with hijacked planes.[23][24] He initially denied his role in the attacks, but later recanted his denial.[25]
Al Jazeera broadcast a statement by bin Laden on September 16, 2001: "I stress that I have not carried out this act, which appears to have been carried out by individuals with their own motivation."[26] U.S. forces recovered a videotape in which bin Laden, talking to Khaled al-Harbi, admitted foreknowledge of the attacks.[27] In a 2004 video, he confirmed that he had organized 9/11.[28][29] A video by Al Jazeera in 2006 shows bin Laden with one of the attacks' chief planners, Ramzi bin al-Shibh, as well as hijackers Hamza al-Ghamdi and Wail al-Shehri amid preparations for the attacks.[30]
Motives
Bin Laden's 1996 fatwa, in addition to similar statements that called for the killing of Americans, are seen by investigators as evidence of his motivation for the attacks.[31][32][33] In a second fatwa in 1998, he outlined more of his objections to American foreign policy, such as American support of Israel[32] and the U.S. and other nations' sanctions against Iraq, condemning the "protracted blockade" that he said constituted a declaration of war against "Allah, his messenger, and Muslims."[34] He claimed that the U.S. was being directed by an international Jewish conspiracy into killing as many Muslims as possible[35][36] and that all Muslims must wage a defensive war against the U.S. to combat its aggression against them.[37] This was to be done until the aggression ceased.[32][38] Bin Laden further believed it would send a message to the American people, forcing the U.S. to reevaluate its policies.[39] In a 1998 interview with American journalist John Miller, he stated:[40]
American history does not distinguish between civilians and military, not even women and children. They are the ones who used [a nuclear bomb] against Nagasaki. Can these bombs distinguish between infants and military? America does not have a religion that will prevent it from destroying all people. So we tell the Americans as people and we tell the mothers of soldiers and American mothers in general that if they value their lives and the lives of their children, to find a nationalist government that will look after their interests and not the interests of the Jews.
After 9/11, bin Laden maintained that women and children were not targeted in the attack—rather, symbols of America's "economic and military power."[41][42] In December 2001, a video of bin Laden was released in which he did not admit responsibility for 9/11, but instead said:[43][44]
It has become clear that the West in general and America in particular have an unspeakable hatred for Islam. [...] It is the hatred of crusaders. Terrorism against America deserves to be praised because it was a response to injustice, aimed at forcing America to stop its support for Israel, which kills our people. [...] We say that the end of the United States is imminent, whether bin Laden or his followers are alive or dead, for the awakening of the Muslim ummah [nation] has occurred. [...] It is important to hit the economy [of the U.S.], which is the base of its military power... If the economy is hit, they will become reoccupied.
In a 2002 manifesto, he listed multiple factors implied to have motivated 9/11, including U.S. support of Israel against Lebanon during their occupation of Southern Lebanon and Palestinians during the Second Intifada, support of the Philippines against Muslim militants, support of Russia against Muslim militants, and support of India against Muslim civilians in Kashmir. He also listed the former U.S.-led intervention against Muslim militants in Somalia, pollution caused by the U.S., and the U.S.' refusal to ratify the Kyoto Protocol.[45] In the 2004 video, he said he was inspired to destroy the World Trade Center's Twin Towers after watching the destruction of towers in Lebanon by Israel during the 1982 Lebanon War.[28][46]
"God knows it did not cross our minds to attack the towers, but after [witnessing] [...] the destroyed towers in Lebanon, it occurred to me punish the unjust the same way: to destroy towers in America, so it could taste some of what we are tasting, and to stop killing our children and women."[47]
Other motives have been suggested in addition to those stated by him and other al-Qaeda members. Some authors suggested the "humiliation" that resulted from the Islamic world falling behind the Western world—this discrepancy was rendered especially visible by globalization[48][49]—as well as a desire to provoke the U.S. into a broader war against the Islamic world in the hope of motivating more allies to support al-Qaeda. Similarly, others have argued the 9/11 attacks were a strategic move to provoke America into a war that would incite a pan-Islamic revolution.[50][51]
Khalid Sheikh Mohammed and other al-Qaeda members
In April 2002, Yosri Fouda of Al Jazeera met al-Qaeda member Khalid Sheikh Mohammed and Ramzi bin al-Shibh, who were in hiding, and they admitted to him their involvement in the attacks.[52][53][54] Before 9/11, Mohammed had been an organizer and financier of al-Qaeda's 1993 bombing of the World Trade Center, and he was the uncle of Ramzi Yousef, the lead bomber in that attack.[55][56] In the Bojinka plot, Mohammed and Yousef then moved on to plan a new terrorist attack planned for January 1995. Despite its failure, as well as Yousef's imprisonment by the U.S. afterwards, the plot would influence the later 9/11 attacks.[57] The 2004 9/11 Commission Report determined that the animosity that Mohammed, the principal architect of 9/11, felt towards the U.S. had stemmed from his "violent disagreement with U.S. foreign policy favoring Israel."[58]
Planning
Documents seized during the 2011 operation that killed bin Laden included notes handwritten by bin Laden in September 2002 with the heading "The Birth of the Idea of September 11." He describes how he was inspired by the crash of EgyptAir Flight 990 in October 1999, which was deliberately crashed by co-pilot Gameel Al-Batouti, killing more than 200 passengers. "This is how the idea of 9/11 was conceived and developed in my head, and that is when we began the planning" bin Laden continued, adding that no one but Mohammed Atef and Abu al-Khair knew about it at the time. The 9/11 Commission Report identified Khalid Sheikh Mohammed as the architect of 9/11, but he is not mentioned in bin Laden's notes.[59]
During the trial of alleged 9/11 conspirator Zacarias Moussaoui, the U.S. government identified five people as having been completely aware of the operation's details; Osama bin Laden, Khalid Sheikh Mohammed, Mohammed Atef, Abu Turab al-Urduni, and Ramzi bin al-Shibh.[60] The attacks were conceived by Khalid Sheikh Mohammed, who first presented it to bin Laden in 1996.[61] Many targets were listed that al-Qaeda hijackers could crash planes into, including the Library Tower (now the U.S. Bank Tower) in Los Angeles.[62][63] Bin Laden rejected the plan for being too elaborate.[64][page needed][65] Al-Qaeda's first attacks against the U.S. after Bin Laden's 1998 fatwa were the 1998 African embassy bombings.[66] In late 1998 or early 1999, bin Laden approved Mohammed to go forward with a new version of the 1996 plan.[67][21]
Bin Laden provided leadership and financial support, and was involved in selecting participants.[68] Atef provided operational support, including target selections and helping arrange travel for the hijackers.[69] He initially selected Nawaf al-Hazmi and Khalid al-Mihdhar, both experienced jihadists who had fought in the Bosnian war. The two arrived in the United States in mid-January 2000. In early 2000, they took flying lessons in San Diego, California. Both spoke little English. They performed poorly in flying lessons, and so they eventually served as secondary "muscle" hijackers.[70][71]
The Hamburg cell in Germany included Islamists who were key operatives in the 9/11 attacks.[72] In late 1999, cell members bin al-Shibh, Mohamed Atta, Marwan al-Shehhi, and Ziad Jarrah arrived to meet al-Qaeda in Afghanistan.[73][74] Bin Laden selected these men because they were educated, could speak English, and had experience living in the West.[75] New recruits were routinely screened for special skills and al-Qaeda leaders consequently discovered that Hani Hanjour already had a commercial pilot's license.[76]
Hanjour arrived in San Diego on December 8, 2000, joining al-Hazmi.[77]: 6–7 They soon left for Arizona, where Hanjour took refresher training.[77]: 7 Marwan al-Shehhi arrived at the end of May 2000, while Atta arrived on June 3, 2000, and Jarrah arrived on June 27, 2000.[77]: 6 Bin al-Shibh applied several times for a visa to the United States, but as a Yemeni, he was rejected out of concerns he would overstay his visa.[77]: 4, 14 Bin al-Shibh stayed in Hamburg, providing coordination between Atta and Mohammed.[77]: 16 The three Hamburg cell members all took pilot training in South Florida at Huffman Aviation.[77]: 6
In the spring of 2001, the secondary hijackers began arriving in the United States.[78] In July 2001, Atta met with bin al-Shibh in Spain, where they coordinated details of the plot, including final target selection. Bin al-Shibh passed along bin Laden's wish for the attacks to be carried out as soon as possible.[79] Some of the hijackers received passports from corrupt Saudi officials who were family members or used fraudulent passports to gain entry.[80]
Prior intelligence
In late 1999, al-Qaeda associate Walid bin Attash ("Khallad") contacted al-Mihdhar and told him to meet in Kuala Lumpur, Malaysia; al-Hazmi and Abu Bara al Yemeni would also be in attendance. The NSA intercepted a telephone call mentioning the meeting, al-Mihdhar, and the name "Nawaf" (al-Hazmi); while the agency feared "Something nefarious might be afoot", it took no further action.[81]
The CIA had already been alerted by Saudi intelligence about al-Mihdhar and al-Hazmi being al-Qaeda members. A CIA team broke into al-Mihdhar's Dubai hotel room and discovered that Mihdhar had a U.S. visa. While Alec Station alerted intelligence agencies worldwide, it did not share this information with the FBI. The Malaysian Special Branch observed the January 5, 2000, meeting of the two al-Qaeda members and informed the CIA that al-Mihdhar, al-Hazmi, and Khallad were flying to Bangkok, but the CIA never notified other agencies of this, nor did it ask the State Department to put al-Mihdhar on its watchlist. An FBI liaison asked permission to inform the FBI of the meeting but was told: "This is not a matter for the FBI."[82]
By late June, senior counter-terrorism official Richard Clarke and CIA director George Tenet were "convinced that a major series of attacks was about to come", although the CIA believed the attacks would likely occur in Saudi Arabia or Israel.[83] In early July, Clarke put domestic agencies on "full alert", telling them, "Something spectacular is going to happen here, and it's going to happen soon." He asked the FBI and the State Department to alert the embassies and police departments, and the Defense Department to go to "Threat Condition Delta."[84][85] Clarke later wrote:
Somewhere in CIA there was information that two known al-Qaeda terrorists had come into the United States. Somewhere in the FBI, there was information that strange things had been going on at flight schools in the United States. [...] They had specific information about individual terrorists from which one could have deduced what was about to happen. None of that information got to me or the White House.[86]
[...] by July [2001], with word spreading of a coming attack, a schism emerged among the senior leadership of al Qaeda. Several senior members reportedly agreed with Mullah Omar. Those who reportedly sided with bin Ladin included Atef, Sulayman Abu Ghayth, and Khalid Sheikh Mohammed. But those said to have opposed him were weighty figures in the organization-including Abu Hafs the Mauritanian, Sheikh Saeed al Masri, and Sayf al Adl. One senior al Qaeda operative claims to recall Bin Ladin arguing that attacks against the United States needed to be carried out immediately to support insurgency in the Israeli-occupied territories and protest the presence of U.S. forces in Saudi Arabia.
On July 13, Tom Wilshire, a CIA agent assigned to the FBI's international terrorism division, emailed his superiors at the CIA's Counterterrorism Center (CTC) requesting permission to inform the FBI that Hazmi was in the country and that Mihdhar had a U.S. visa. The CIA never responded.[88]
The same day, Margarette Gillespie, an FBI analyst working in the CTC, was told to review material about the Malaysia meeting. She was not told of the participant's presence in the U.S. The CIA gave Gillespie surveillance photos of Mihdhar and Hazmi from the meeting to show to FBI counterterrorism but did not tell her their significance. The Intelink database informed her not to share intelligence material with criminal investigators. When shown the photos, the FBI refused more details on their significance, and they were not given Mihdhar's date of birth or passport number.[89] In late August 2001, Gillespie told the INS, the State Department, the Customs Service, and the FBI to put Hazmi and Mihdhar on their watchlists, but the FBI was prohibited from using criminal agents in searching for the duo, hindering their efforts.[90]
Also in July, a Phoenix-based FBI agent sent a message to FBI headquarters, Alec Station, and FBI agents in New York alerting them to "the possibility of a coordinated effort by Osama bin Laden to send students to the United States to attend civil aviation universities and colleges." The agent, Kenneth Williams, suggested the need to interview flight school managers and identify all Arab students seeking flight training.[91] In July, Jordan alerted the U.S. that al-Qaeda was planning an attack on the U.S.; "months later", Jordan notified the U.S. that the attack's codename was "The Big Wedding" and that it involved airplanes.[92]
On August 6, 2001, the CIA's Presidential Daily Brief, designated "For the President Only", was entitled Bin Ladin Determined To Strike in US. The memo noted that FBI information "indicates patterns of suspicious activity in this country consistent with preparations for hijackings or other types of attacks."[93]
In mid-August, one Minnesota flight school alerted the FBI about Zacarias Moussaoui, who had asked "suspicious questions." The FBI found that Moussaoui was a radical who had traveled to Pakistan, and the INS arrested him for overstaying his French visa. Their request to search his laptop was denied by FBI headquarters due to the lack of probable cause.[94]
The failures in intelligence-sharing were attributed to 1995 Justice Department policies limiting intelligence-sharing, combined with CIA and NSA reluctance to reveal "sensitive sources and methods" such as tapped phones.[95] Testifying before the 9/11 Commission in April 2004, then-Attorney General John Ashcroft recalled that the "single greatest structural cause for the September 11th problem was the wall that segregated or separated criminal investigators and intelligence agents."[96] Clarke also wrote: "[T]here were ... failures to get information to the right place at the right time."[97]
Attacks
Early on the morning of Tuesday, September 11, 2001, nineteen hijackers took control of four commercial airliners (two Boeing 757s and two Boeing 767s).[98] Large planes with long flights were selected for hijacking because they would have more fuel.[99]
| Operator | Flight number | Aircraft type | Time of departure* | Time of crash* | Departed from | En route to | Crash site | Fatalities | ||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Crew | Passengers† | Ground§ | Hijackers | Total‡ | ||||||||
| American Airlines | 11 | Boeing 767-223(ER)[k] | 7:59 a.m. | 8:46 a.m. | Logan International Airport | Los Angeles International Airport | North Tower of the World Trade Center, floors 93 to 99 | 11 | 76 | 2,606 | 5 | 2,763 |
| United Airlines | 175 | Boeing 767–222[l] | 8:14 a.m. | 9:03 a.m.[h] | Logan International Airport | Los Angeles International Airport | South Tower of the World Trade Center, floors 77 to 85 | 9 | 51 | 5 | ||
| American Airlines | 77 | Boeing 757–223[m] | 8:20 a.m. | 9:37 a.m. | Washington Dulles International Airport | Los Angeles International Airport | West wall of Pentagon | 6 | 53 | 125 | 5 | 189 |
| United Airlines | 93 | Boeing 757–222[n] | 8:42 a.m. | 10:03 a.m. | Newark International Airport | San Francisco International Airport | Field in Stonycreek Township near Shanksville | 7 | 33 | 0 | 4 | 44 |
| Totals | 33 | 213 | 2,731 | 19 | 2,996 | |||||||
* Eastern Daylight Time (UTC−04:00)
† Excluding hijackers
§ Including emergency workers
‡ Including hijackers
Crashes
_(right).jpg)
At 7:59 a.m., American Airlines Flight 11 took off from Logan International Airport in Boston.[101] About fifteen minutes into the flight, five hijackers armed with boxcutters took over the plane, injuring at least three people (and possibly killing one)[102][103][104] before forcing their way into the cockpit. The terrorists also displayed an apparent explosive and sprayed mace into the cabin, to frighten the hostages into submission and further hinder resistance.[105] Back at Logan, United Airlines Flight 175 took off at 8:14 a.m.[106] Hundreds of miles southwest at Dulles International Airport, American Airlines Flight 77 left the runway at 8:20 a.m.[106] Flight 175's journey proceeded normally for 28 minutes until 8:42 am, when a group of five hijacked the plane, murdering both pilots and stabbing several crew members before assuming control of the aircraft. These hijackers also used bomb threats to instill fear into the passengers and crew,[107] also spraying "tear gas, pepper spray or another irritant" in the cabin to force passengers and flight attendants to the rear of the cabin.[108] Concurrently, United Airlines Flight 93 departed from Newark International Airport in New Jersey;[106] originally scheduled to pull away from the gate at 8:00 a.m., the plane was running 42 minutes late.[109] At 8:46 a.m., Flight 11 was deliberately crashed into the north face of the World Trade Center's North Tower between the 93rd and 99th floors.[110] The initial presumption by many was that it was an accident.[111] At 8:51 a.m., American Airlines Flight 77 was also taken over by five hijackers who forcibly entered the cockpit 31 minutes after take-off.[112] Although they were equipped with knives,[113] there were no reports of anyone on board being stabbed, nor did the two people who made phone calls mention the use of mace or a bomb threat. Flight 175 was flown into the South Tower's southern facade (2 WTC) between the 77th and 85th floors[114] at 9:03 a.m.,[h] demonstrating that the first crash was a deliberate act of terrorism.[115][116]
Four men aboard Flight 93 struck suddenly, killing at least one passenger, after having waited 46 minutes—a holdup that proved disastrous for the terrorists when combined with the delayed takeoff.[117] They stormed the cockpit and seized control of the plane at 9:28 a.m., turning the plane eastbound towards Washington, D.C.[118] Much like their counterparts on the first two flights, the fourth team used bomb threats and filled the cabin with mace.[119]
Nine minutes after Flight 93 was hijacked, Flight 77 crashed into the west side of the Pentagon at 9:37 a.m.[120] Because of the two delays,[121] the passengers and crew of Flight 93 had time to learn of the previous attacks through phone calls to the ground, and, as a result, an uprising was hastily organized to take control of the aircraft at 9:57 a.m.[122] Passengers and crew began a counterattack to retake control of the aircraft. As the revolt reached the cockpit door, the hijacker-pilot began violently pitching and rolling the aircraft to disrupt the assault. The struggle continued until 10:03:11 a.m., when the aircraft crashed into a field in Stonycreek Township, near Shanksville, Pennsylvania, following a final roll onto its back, failing to reach the hijackers' intended target in Washington, D.C.[123][124] The plane was about twenty minutes away from reaching D.C. at the time of the crash, and its target is believed to have been either the Capitol Building or the White House.[99][122]
Some passengers and crew who called from the aircraft using the cabin air phone service and mobile phones provided details: several hijackers were aboard each plane; they used mace, tear gas, or pepper spray to overcome attendants; and some people aboard had been stabbed.[125] Reports indicated hijackers stabbed and killed pilots, flight attendants, and one or more passengers.[98][126] According to the 9/11 Commission's final report, the hijackers had recently purchased multi-function hand tools and assorted Leatherman-type utility knives with locking blades (which were not forbidden to passengers at the time), but these were not found among the possessions left behind by the hijackers.[127][128] A flight attendant on Flight 11, a passenger on Flight 175, and passengers on Flight 93 said the hijackers had bombs, but one of the passengers said he thought the bombs were fake. The FBI found no traces of explosives at the crash sites, and the 9/11 Commission concluded that the bombs were probably fake.[98] On at least two of the hijacked flights—American 11 and United 93—the terrorists claimed over the PA system that they were taking hostages and were returning to the airport to have a ransom demand met, a clear attempt to prevent passengers from fighting back. Both attempts failed, however, as both hijacker pilots in these instances (Mohamed Atta[129] and Ziad Jarrah,[130] respectively) mistakenly transmitted their messages to ATC instead of the people on the plane as intended, tipping off the flight controllers that the planes had been hijacked.
.png)
Three buildings in the World Trade Center collapsed due to fire-induced structural failure. Although the South Tower was struck around seventeen minutes after the North Tower, the plane's impact zone was far lower, at a much faster speed, and into a corner, with the unevenly-balanced additional structural weight causing it to collapse first at 9:59 a.m.,[131]: 80 [132]: 322 having burned for exactly 56 minutes[o] in the fire caused by the crash of United Airlines Flight 175 and the explosion of its fuel. The North Tower lasted another 29 minutes and 24 seconds before collapsing at 10:28 a.m.,[p] one hour, forty-one minutes, and fifty-three seconds[i] after being struck by American Airlines Flight 11. When the North Tower collapsed, debris fell on the nearby 7 World Trade Center building (7 WTC), damaging the building and starting fires. These fires burned for nearly seven hours, compromising the building's structural integrity, and 7 WTC collapsed at 5:21 p.m.[135][136] The west side of the Pentagon sustained significant damage.[137] At 9:42 a.m., the Federal Aviation Administration (FAA) grounded all civilian aircraft within the continental U.S., and civilian aircraft already in flight were told to land immediately.[138] All international civilian aircraft were either turned back or redirected to airports in Canada or Mexico, and were banned from landing on United States territory for three days.[139] The attacks created widespread confusion among news organizations and air traffic controllers. Among unconfirmed and often contradictory news reports aired throughout the day, one of the most prevalent claimed a car bomb had been detonated at the U.S. State Department's headquarters in Washington, D.C.[140] Another jet (Delta Air Lines Flight 1989) was suspected of having been hijacked, but the aircraft responded to controllers and landed safely in Cleveland, Ohio.[141]
In an April 2002 interview, Khalid Sheikh Mohammed and Ramzi bin al-Shibh, who are believed to have organized the attacks, said Flight 93's intended target was the United States Capitol, not the White House.[142] During the planning stage of the attacks, Mohamed Atta (Flight 11's hijacker and pilot) thought the White House might be too tough a target and sought an assessment from Hani Hanjour (who hijacked and piloted Flight 77).[143] Mohammed said al-Qaeda initially planned to target nuclear installations rather than the World Trade Center and the Pentagon, but decided against it, fearing things could "get out of control."[144] Final decisions on targets, according to Mohammed, were left in the hands of the pilots.[143] If any pilot could not reach his intended target, he was to crash the plane.[99]
Casualties
The attack on the World Trade Center's North Tower alone[q] made 9/11 the deadliest act of terrorism in history.[146] Taken together, the four crashes killed 2,996 people (including the hijackers) and injured thousands more.[147] The death toll included 265 on the four planes (from which there were no survivors); 2,606 in the World Trade Center and the surrounding area; and 125 at the Pentagon.[148][149] Most who died were civilians, as well as 343 firefighters, 72 law enforcement officers, 55 military personnel, and the 19 terrorists.[150][151] More than 90 countries lost citizens in the attacks.[152]
In New York City, more than 90% of those who died in the towers had been at or above the points of impact. In the North Tower, between 1,344[153] and 1,402 people were at, above or one floor below the point of impact and all died. Hundreds were killed instantly when the plane struck.[154] The estimated 800 people[155] who survived the impact were trapped and died in the fires or from smoke inhalation, fell or jumped from the tower to escape the smoke and flames, or were killed in the building's collapse. The destruction of all three staircases in the North Tower when Flight 11 hit made it impossible for anyone from the impact zone upward to escape. 107 people not trapped by the impact died.[156] When Flight 11 struck between floors 93 and 99, the 92nd floor was rendered inescapable: the crash severed all elevator shafts while falling debris blocked the stairwells, ensuring the deaths of all 69 workers on the floor.