On September 11, 2001, a series of four coordinated terrorist attacks were carried out by the Islamist extremist group al-Qaeda against the United States. The attackers hijacked four commercial airliners, intentionally crashing two into the Twin Towers of the World Trade Center in New York City and a third into the Pentagon in Arlington, Virginia. The attacks resulted in the collapse of the World Trade Center towers and significant damage to the Pentagon.
The sequence of events began at 8:46 AM (EDT) when American Airlines Flight 11 struck the North Tower of the World Trade Center. At 9:03 AM, United Airlines Flight 175 hit the South Tower. A third plane, American Airlines Flight 77, crashed into the western side of the Pentagon at 9:37 AM. The fourth hijacked plane, United Airlines Flight 93, was intended for a target in Washington, D.C., but crashed into a field in Shanksville, Pennsylvania, at 10:03 AM after passengers and crew fought back against the hijackers. The attacks resulted in 2,977 fatalities, making it the deadliest terrorist attack in world history.
The immediate consequence of the attacks was the initiation of the U.S. "War on Terror," which led to the invasion of Afghanistan to dismantle al-Qaeda and depose the Taliban regime that harbored it. The event fundamentally reshaped American foreign policy and led to extensive changes in global security and aviation protocols. Domestically, it prompted the creation of the Department of Homeland Security and the passage of new legislation, such as the Patriot Act, significantly expanding government surveillance powers.
