American Airlines Flight 77

American Airlines Flight 77 was a scheduled domestic flight from Washington Dulles International Airport to Los Angeles International Airport on September 11, 2001. The Boeing 757-223, registered N644AA, took off at 08:20 EDT with 58 passengers, including five hijackers, and a crew of six led by Captain Charles Burlingame and First Officer David Charlebois.

Approximately 31 minutes after takeoff, the hijackers stormed the cockpit and forced passengers and crew toward the rear of the cabin. Lead hijacker Hani Hanjour, who had trained extensively as a pilot, took control of the aircraft. Because air traffic controllers at Indianapolis Center were not yet aware that hijackings were underway elsewhere, Flight 77's disappearance from radar near southwestern West Virginia was initially treated as a possible crash, and search-and-rescue resources were misdirected accordingly.

While the hijacking was underway, two people aboard made phone calls without the hijackers' knowledge. Flight attendant Renee May called her mother, and passenger Barbara Olson called her husband, then-Solicitor General Theodore Olson, describing the hijacking and the weapons the hijackers carried. Hanjour ultimately flew the aircraft into the western side of the Pentagon in Arlington County, Virginia, at 09:37, after executing a descending turn detected on radar at Dulles. The impact and resulting fire killed all 64 people aboard the aircraft and 125 people inside the Pentagon, for a combined death toll of 189. A portion of the Pentagon's west side later collapsed as a result of the fire.

Rescue operations were led initially by military and civilian personnel inside the building, with the Arlington County Fire Department assuming command within about ten minutes. Investigators, including the FBI's Washington Field Office and National Capital Response Squad, later took over the crime scene from fire officials. The Armed Forces Medical Examiner's office identified remains of 179 of the victims; overall, 184 of 189 people who died were identified. In 2002, unidentified remains of 25 victims were interred collectively at Arlington National Cemetery beneath a memorial marker inscribed with the names of all who died.

The flight's two "black boxes" were recovered from the wreckage; the cockpit voice recorder's magnetic tape was too damaged to yield usable audio, but data was recovered from the flight data recorder. The damaged section of the Pentagon was rebuilt and reoccupied by August 2002. An outdoor Pentagon Memorial, containing a bench for each of the 184 people killed in the building and aboard the aircraft, was dedicated on September 11, 2008.

Flight 77 was the third of four aircraft hijacked that morning as part of the coordinated September 11 attacks carried out by al-Qaeda, and was the only one of the two aircraft targeting Washington, D.C. (Flight 77 and United Airlines Flight 93) to reach its intended target.