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.
American Airlines Flight 11
The 9/11 Commission estimated that the hijacking began at 08:14, when the pilots stopped responding to requests from the Boston Air Route Traffic Control Center (Boston ARTCC). It is believed that Waleed al-Shehri made the first move. At 08:13:29, as the aircraft was passing over central Massachusetts at , the pilots responded to a request from Boston ARTCC to make a 20-degree turn to the right. At 08:13:47, Boston ARTCC told the pilots to ascend to a cruising altitude of but received no response. It is believed that Captain Ogonowski was stabbed to death in order for the hijacker pilot Mohamed Atta to take control of the plane and crash it into the North Tower of the World Trade Center. Before dying, Ogonowski keyed the cockpit microphone; "pushing its button intermittently to signal that something was wrong and at one point allowing them to hear the voice of the hijacker." At 08:16, the aircraft leveled off at and shortly thereafter deviated from its scheduled path. Boston ARTCC made multiple attempts to talk to Flight 11 without reply, and at 08:21, the flight stopped transmitting its Mode-C transponder signal.