What happened in Washington DC on September 11th 2001?

On September 11, 2001, a coordinated terrorist attack by the extremist group al-Qaeda targeted the United States. In Washington, D.C., American Airlines Flight 77 crashed into the Pentagon, the headquarters of the U.S. Department of Defense, causing significant destruction and loss of life. This attack was part of a larger assault that included the World Trade Center in New York City, resulting in nearly 3,000 deaths and leading to widespread changes in U.S. security and foreign policy.