What major event happened on September 11, 2001?

On September 11, 2001, a significant and tragic event took place when terrorists carried out coordinated attacks against the United States. This day is marked in history due to the hijacking of four commercial airplanes by members of the extremist group al-Qaeda. Two planes were flown into the twin towers of the World Trade Center in New York City, leading to their eventual collapse. A third plane hit the Pentagon, the United States Department of Defense headquarters, while the fourth crashed into a field in Pennsylvania after passengers attempted to regain control from the hijackers.

These attacks resulted in the deaths of nearly 3,000 people and initiated a shift in U.S. foreign and domestic policy, including the launch of the War on Terror. This day profoundly impacted not just the United States but also the world, changing how nations approached security and relations concerning terrorism. Understanding the gravity of the events of September 11 is crucial for grasping subsequent political, social, and cultural developments.