candidate: On September 11 , 2001 , the 60th anniversary of The Pentagon 's groundbreaking , a team of five al - Qaeda affiliated hijackers took control of American Airlines Flight 77 , " en route " from Washington Dulles International Airport to Los Angeles International Airport , and deliberately crashed the Boeing 757 airliner into the western side of the Pentagon at 9:37 am EDT as part of the September 11 attacks .