American Airlines Flight 77

American Airlines Flight 77 was a passenger flight which was hijacked by five al-Qaeda terrorists on September 11, 2001, as part of the September 11 attacks. They deliberately crashed it into the Pentagon near Washington, D.C., killing all 59 people on board plus the hijackers, as well as 125 people in the building. The aircraft involved, a Boeing 757-223, was flying American Airlines' daily scheduled morning transcontinental service from Washington Dulles International Airport, in Dulles, Virginia to Los Angeles International Airport in Los Angeles, California.

Less than 35 minutes into the flight, the hijackers stormed the cockpit and forced the passengers, crew, and pilots to the rear of the aircraft. Hani Hanjour, one of the hijackers who was trained as a pilot, assumed control of the flight. Unknown to the hijackers, passengers aboard were able to make telephone calls to loved ones and relay information on the hijacking.

The aircraft crashed into the western side of the Pentagon at 09:37 EDT. Dozens of people witnessed the crash and news sources began reporting on the incident within minutes. The impact severely damaged an area of the Pentagon and caused a large fire. At 10:10AM, a portion of the Pentagon collapsed; firefighters spent days trying to fully extinguish the blaze. The damaged sections of the Pentagon were rebuilt in 2002, with occupants moving back into the completed areas on August 15, 2002.

The 184 victims of the attack are memorialized in the Pentagon Memorial adjacent to the Pentagon. The 1.93-acre (7,800 m2) park contains a bench for each of the victims, arranged according to their year of birth, ranging from 1930 (age 71) to 1998 (age 3).