The World Trade Center crashes killed 2,753, the vast majority of fatalities being occupants of the two towers or emergency personnel responding to the disaster. In addition, 184 were killed by the impact of American Airlines Flight 77, which crashed into the Pentagon in Arlington, Virginia, causing severe damage and partial destruction to the building's west side. The crash of United Airlines Flight 93 into a field in Somerset County, Pennsylvania, killed all 40 passengers and crew aboard the aircraft, after the hijackers crashed it to prevent it from being retaken by the passengers.