What major event happened on September 11, 2001?

On September 11, 2001, a significant and tragic event unfolded when terrorists attacked the United States, marking a pivotal moment in both American history and global politics. Coordinated actions by the extremist group al-Qaeda led to the hijacking of four commercial airplanes, two of which were flown into the World Trade Center towers in New York City, ultimately causing their collapse. A third plane struck the Pentagon in Arlington, Virginia, and the fourth plane, United Airlines Flight 93, crashed into a field in Pennsylvania after passengers attempted to regain control from the hijackers. This series of attacks resulted in the deaths of nearly 3,000 people and initiated widespread changes in U.S. domestic and foreign policy, including the launch of the War on Terror, increased security measures, and significant shifts in international relations. The impact of this day is still felt today as it shaped discussions on security, civil liberties, and anti-terrorism legislation.