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.
September 11 attacks advance-knowledge conspiracy theories
There have also been allegations that the hijackers' preparations may have been given assistance by U.S. intelligence. According to CBS News, "two of the Sept. 11 hijackers who lived in San Diego in 2000 rented a room from a man who reportedly worked as an undercover FBI informant... the FBI informant prayed with them and even helped one open a bank account." Doubts have been raised about the speed with which the hijackers were identified, leading to suggestions that the FBI already had the names of the hijackers in advance. In his book "Against All Enemies", Richard Clarke said that at 9:59 am on September 11, which is the time when WTC2 collapsed and 8 minutes before NORAD even knew Flight 93 had been hijacked, the FBI already had a list of the 19 alleged hijackers. A former high-level intelligence official said that "Whatever trail was left was left deliberately—for the F.B.I. to chase."