War in Afghanistan (2001–present)
On the morning of 11 September 2001, a total of 19 Arab men—15 of whom were from Saudi Arabia—carried out four coordinated attacks in the United States. Four commercial passenger jet airliners were hijacked. The hijackers – members of al-Qaeda's Hamburg cell – intentionally crashed two of the airliners into the Twin Towers of the World Trade Center in New York City, killing everyone on board and more than 2,000 people in the buildings. Both buildings collapsed within two hours from damage related to the crashes, destroying nearby buildings and damaging others. The hijackers crashed a third airliner into the Pentagon in Arlington, Virginia, just outside Washington, D.C. The fourth plane crashed into a field near Shanksville, in rural Pennsylvania, after some of its passengers and flight crew attempted to retake control of the plane, which the hijackers had redirected toward Washington, D.C., to target the White House, or the U.S. Capitol. No one aboard the flights survived. According to the New York State Health Department, the death toll among responders including firefighters and police was 836 as of June 2009. Total deaths were 2,996, including the 19 hijackers.
September 11 attacks
Immediately after the attacks, the Federal Bureau of Investigation started PENTTBOM, the largest criminal inquiry in the history of the United States. At its height, more than half of the FBI's agents worked on the investigation and followed a half-million leads. The FBI concluded that there was "clear and irrefutable" evidence linking al-Qaeda and bin Laden to the attacks.
The FBI was quickly able to identify 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 papers that amounted to the Rosetta stone of the investigation", said one FBI agent. Within hours of the attacks, the FBI released the names and in many cases the personal details of the suspected pilots and hijackers. On September 27, 2001, they released photos of all 19 hijackers, along with information about possible nationalities and aliases. Fifteen of the men were from Saudi Arabia, two from the United Arab Emirates, one from Egypt, and one from Lebanon.