United States invasion of Afghanistan
On the morning of 11 September 2001, al-Qaeda carried out four coordinated attacks on 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. Both buildings collapsed within two hours from fire damage related to the crashes, destroying nearby buildings and damaging others. The hijackers crashed a third airliner into the Pentagon in Arlington County, Virginia. The fourth plane crashed into a field near Shanksville, 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 United States Capitol. No flights had survivors. In total, 2,996 people, including the 19 hijackers, died and more than 6,000 others injured in the attacks. According to the New York State Health Department, 836 first responders, including firefighters and police personnel, had died as of June 2009.
Responsibility for the September 11 attacks
Intelligence experts speak of a "short list" of prime suspects—groups that possess both the means and the motive to carry out the crime. Two of the passengers had been identified as al-Qaeda members and were on the FBI's terrorist-alert list prior to 9/11: Khalid Almihdhar and Nawaf Alhazmi. It appears certain that all hijackers had Arab origins, and none were Afghan; moreover, both in their immense scale, careful planning and refraining from claiming responsibility, the attacks are reminiscent of al-Qaeda's previous attacks such as the 1998 US embassy bombings that killed over 200 people.