September 11 attacks

The September 11 attacks (often referred to as 9/11) were a series of four coordinated terrorist attacks by the Islamic terrorist group al-Qaeda against the United States on the morning of Tuesday, September 11, 2001. The attacks resulted in 2,977 fatalities, over 25,000 injuries, and substantial long-term health consequences, in addition to at least $10 billion in infrastructure and property damage. 9/11 is the single deadliest terrorist attack in human history and the single deadliest incident for firefighters and law enforcement officers in the history of the United States, with 343 and 72 killed, respectively.

Four passenger airliners which had departed from airports in the northeastern United States bound for California were hijacked by 19 al-Qaeda terrorists. Two of the planes, American Airlines Flight 11 and United Airlines Flight 175, crashed into the North and South towers, respectively, of the World Trade Center complex in Lower Manhattan. Within an hour and 42 minutes, both 110-story towers collapsed. Debris and the resulting fires caused a partial or complete collapse of all other buildings in the World Trade Center complex, including the 47-story 7 World Trade Center tower, as well as significant damage to ten other large surrounding structures. A third plane, American Airlines Flight 77, was crashed into the Pentagon (the headquarters of the U.S. Department of Defense) in Arlington County, Virginia, which led to a partial collapse of the building's west side. The fourth plane, United Airlines Flight 93, was initially flown toward Washington, D.C., but crashed into a field in Stonycreek Township, Pennsylvania, after passengers thwarted the hijackers.

Suspicion quickly fell onto al-Qaeda. The United States responded by launching the War on Terror and invading Afghanistan to depose the Taliban, which had failed to comply with U.S. demands to expel al-Qaeda from Afghanistan and extradite their leader Osama bin Laden. Many countries strengthened their anti-terrorism legislation and expanded the powers of law enforcement and intelligence agencies to prevent terrorist attacks. Although bin Laden initially denied any involvement, in 2004 he claimed responsibility for the attacks. Al-Qaeda and bin Laden cited U.S. support of Israel, the presence of U.S. troops in Saudi Arabia, and sanctions against Iraq as motives. After evading capture for almost a decade, bin Laden was located in Pakistan in 2011 and killed during a U.S. military raid.

The destruction of the World Trade Center and nearby infrastructure seriously harmed the economy of New York City and had a significant effect on global markets. Wall Street was closed until September 17, and the U.S. and Canadian civilian airspaces until September 13. Many closings, evacuations, and cancellations followed, out of respect or fear of further attacks. Cleanup of the World Trade Center site was completed in May 2002, and the Pentagon was repaired within a year. The construction of One World Trade Center began in November 2006, and the building opened in November 2014. Numerous memorials have been constructed, including 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

The origins of al-Qaeda can be traced to 1979 when the Soviet Union invaded Afghanistan. Osama bin Laden travelled to Afghanistan and helped to organize Arab mujahideen to resist the Soviets. Under the guidance of Ayman al-Zawahiri, bin Laden became more radical. In 1996, bin Laden issued his first fatwā, calling for American soldiers to leave Saudi Arabia.

In a second fatwā in 1998, bin Laden outlined his objections to American foreign policy with respect to Israel, as well as the continued presence of American troops in Saudi Arabia after the Gulf War. Bin Laden used Islamic texts to exhort Muslims to attack Americans until the stated grievances were reversed. Muslim legal scholars "have throughout Islamic history unanimously agreed that the jihad is an individual duty if the enemy destroys the Muslim countries", according to bin Laden.

Osama bin Laden

Bin Laden orchestrated the attacks and initially denied involvement but later recanted his false statements. Al Jazeera broadcast a statement by bin Laden on September 16, 2001, stating, "I stress that I have not carried out this act, which appears to have been carried out by individuals with their own motivation". In November 2001, U.S. forces recovered a videotape from a destroyed house in Jalalabad, Afghanistan. In the video, bin Laden is seen talking to Khaled al-Harbi and admits foreknowledge of the attacks. On December 27, 2001, a second bin Laden video was released. In the video, he said:

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 umma (nation) has occurred

but he stopped short of admitting responsibility for the attacks.

Shortly before the U.S. presidential election in 2004, bin Laden used a taped statement to publicly acknowledge al-Qaeda's involvement in the attacks on the United States. He admitted his direct link to the attacks and said they were carried out because:

we are free ... and want to regain freedom for our nation. As you undermine our security, we undermine yours.

Bin Laden said he had personally directed his followers to attack the World Trade Center and the Pentagon. Another video obtained by Al Jazeera in September 2006 shows bin Laden with Ramzi bin al-Shibh, as well as two hijackers, Hamza al-Ghamdi and Wail al-Shehri, as they make preparations for the attacks. The U.S. never formally indicted bin Laden for the 9/11 attacks, but he was on the FBI's Most Wanted List for the bombings of the U.S. Embassies in Dar es Salaam, Tanzania, and Nairobi, Kenya. After a 10-year manhunt, U.S. President Barack Obama announced that bin Laden was killed by American special forces in his compound in Abbottabad, Pakistan, on May 1, 2011.

Khalid Sheikh Mohammed

Journalist Yosri Fouda of the Arabic television channel Al Jazeera reported that in April 2002, Khalid Sheikh Mohammed admitted his involvement in the attacks, along with Ramzi bin al-Shibh. The 2004 9/11 Commission Report determined that the animosity towards the United States felt by Mohammed, the principal architect of the 9/11 attacks, stemmed from his "violent disagreement with U.S. foreign policy favoring Israel". Mohammed was also an adviser and financier of the 1993 World Trade Center bombing and the uncle of Ramzi Yousef, the lead bomber in that attack.

Mohammed was arrested on March 1, 2003, in Rawalpindi, Pakistan, by Pakistani security officials working with the CIA. He was then held at multiple CIA secret prisons and Guantanamo Bay where he was interrogated and tortured with methods including waterboarding. During U.S. hearings at Guantanamo Bay in March 2007, Mohammed again confessed his responsibility for the attacks, stating he "was responsible for the 9/11 operation from A to Z" and that his statement was not made under duress.

A letter presented by the lawyers of Khaled Sheikh Mohammed in the U.S. District Court, Manhattan on 26 July 2019 indicated that he was interested in testifying about Saudi Arabia’s role in the 9/11 attacks and helping the victims and families of the victims of 9/11 in exchange for the United States not seeking the death penalty against him. James Kreindler, one of the lawyers for the victims, raised question over the usefulness of Mohammed.

Planning

The attacks were conceived by Khalid Sheikh Mohammed, who first presented it to Osama bin Laden in 1996. At that time, bin Laden and al-Qaeda were in a period of transition, having just relocated back to Afghanistan from Sudan. The 1998 African Embassy bombings and bin Laden's February 1998 fatwā marked a turning point of al-Qaeda's terrorist operation, as bin Laden became intent on attacking the United States.

In late 1998 or early 1999, bin Laden gave approval for Mohammed to go forward with organizing the plot. Mohammed, bin Laden, and bin Laden's deputy Mohammed Atef held a series of meetings in early 1999. Atef provided operational support, including target selections and helping arrange travel for the hijackers. Bin Laden overruled Mohammed, rejecting potential targets such as the U.S. Bank Tower in Los Angeles for lack of time.

Bin Laden provided leadership and financial support, and was involved in selecting participants. He initially selected Nawaf al-Hazmi and Khalid al-Mihdhar, both experienced jihadists who had fought in Bosnia. Hazmi and Mihdhar arrived in the United States in mid-January 2000. In early 2000, Hazmi and Mihdhar took flying lessons in San Diego, California, but both spoke little English, performed poorly in flying lessons, and eventually served as secondary – or "muscle" – hijackers.

In late 1999, a group of men from Hamburg, Germany arrived in Afghanistan; the group included Mohamed Atta, Marwan al-Shehhi, Ziad Jarrah, and Ramzi bin al-Shibh. Bin Laden selected these men because they were educated, could speak English, and had experience living in the West. New recruits were routinely screened for special skills and al-Qaeda leaders consequently discovered that Hani Hanjour already had a commercial pilot's license. Mohammed later said that he helped the hijackers blend in by teaching them how to order food in restaurants and dress in Western clothing.

Hanjour arrived in San Diego on December 8, 2000, joining Hazmi. They soon left for Arizona, where Hanjour took refresher training. Marwan al-Shehhi arrived at the end of May 2000, while Atta arrived on June 3, 2000, and Jarrah arrived on June 27, 2000. 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. Bin al-Shibh stayed in Hamburg, providing coordination between Atta and Mohammed. The three Hamburg cell members all took pilot training in South Florida at Huffman Aviation.

In spring of 2001, the secondary hijackers began arriving in the United States. 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 also passed along bin Laden's wish for the attacks to be carried out as soon as possible. Some of the hijackers received passports from corrupt Saudi officials who were family members, or used fraudulent passports to gain entry.

There is some idea that 9/11 was selected by the hijackers as the date of the attack because of its resemblance to 9-1-1, the phone number to report emergencies in the U.S. However, Lawrence Wright wrote that the hijackers chose it because September 11, 1683 is when the King of Poland began the battle that turned back the Muslim armies from the Ottoman Empire that were attempting to capture Vienna. For Osama bin Laden, this was a date when the West gained some dominance over Islam, and by attacking on this date, he hoped to make a step in Islam "winning" the war for worldwide power and influence.

Attacks

Early on the morning of September 11, 2001, 19 hijackers took control of four commercial airliners (two Boeing 757s and two Boeing 767s) en route to California (three headed to LAX in Los Angeles and one to SFO in San Francisco) after takeoffs from Logan International Airport in Boston, Massachusetts; Newark Liberty International Airport in Newark, New Jersey; and Washington Dulles International Airport in Loudoun and Fairfax counties in Virginia. Large planes with long flights were selected for hijacking because they would be full of fuel.

The four flights were:

- American Airlines Flight 11: a Boeing 767 aircraft, departed Logan Airport at 7:59 a.m. en route to Los Angeles with a crew of 11 and 76 passengers, not including five hijackers. The hijackers flew the plane into the northern facade of the North Tower of the World Trade Center in New York City at 8:46 a.m.

- United Airlines Flight 175: a Boeing 767 aircraft, departed Logan Airport at 8:14 a.m. en route to Los Angeles with a crew of nine and 51 passengers, not including five hijackers. The hijackers flew the plane into the southern facade of the South Tower of the World Trade Center in New York City at 9:03 a.m.

- American Airlines Flight 77: a Boeing 757 aircraft, departed Washington Dulles International Airport at 8:20 a.m. en route to Los Angeles with a crew of six and 53 passengers, not including five hijackers. The hijackers flew the plane into the western facade of the Pentagon in Arlington County, Virginia, at 9:37 a.m.

- United Airlines Flight 93: a Boeing 757 aircraft, departed Newark International Airport at 8:42 a.m. en route to San Francisco, with a crew of seven and 33 passengers, not including four hijackers. As passengers attempted to subdue the hijackers, the aircraft crashed into a field in Stonycreek Township near Shanksville, Pennsylvania, at 10:03 a.m.

Media coverage was extensive during the attacks and aftermath, beginning moments after the first crash into the World Trade Center.

The four crashes

At 8:46 a.m., five hijackers crashed American Airlines Flight 11 into the northern facade of the World Trade Center's North Tower (1 WTC). At 9:03 a.m., another five hijackers crashed United Airlines Flight 175 into the southern facade of the South Tower (2 WTC). Five hijackers flew American Airlines Flight 77 into the Pentagon at 9:37 a.m. A fourth flight, United Airlines Flight 93, crashed near Shanksville, Pennsylvania, southeast of Pittsburgh, at 10:03 a.m. after the passengers fought the four hijackers. Flight 93's target is believed to have been either the Capitol or the White House. Flight 93's cockpit voice recorder revealed crew and passengers tried to seize control of the plane from the hijackers after learning through phone calls that Flights 11, 77, and 175 had been crashed into buildings that morning. Once it became evident that the passengers might gain control, the hijackers rolled the plane and intentionally crashed it.

Some passengers and crew members 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. Reports indicated hijackers stabbed and killed pilots, flight attendants, and one or more passengers. 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 were not found among the possessions left behind by the hijackers. 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.

Three buildings in the World Trade Center collapsed due to fire-induced structural failure. The South Tower collapsed at 9:59 a.m. after burning for 56 minutes in a fire caused by the impact of United Airlines Flight 175 and the explosion of its fuel. The North Tower collapsed at 10:28 a.m. after burning for 102 minutes. When the North Tower collapsed, debris fell on the nearby 7 World Trade Center building (7 WTC), damaging it and starting fires. These fires burned for hours, compromising the building's structural integrity, and 7 WTC collapsed at 5:21 p.m. The west side of the Pentagon sustained significant damage.

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. 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. The attacks created widespread confusion among news organizations and air traffic controllers. Among the unconfirmed and often contradictory news reports aired throughout the day, one of the most prevalent said a car bomb had been detonated at the U.S. State Department's headquarters in Washington, D.C. 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.

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. During the planning stage of the attacks, Mohamed Atta, the hijacker and pilot of Flight 11, thought the White House might be too tough a target and sought an assessment from Hani Hanjour (who hijacked and piloted Flight 77). 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". Final decisions on targets, according to Mohammed, were left in the hands of the pilots. If any pilot could not reach his intended target, he was to crash the plane.