On 4 April 1975,[note 1] a Lockheed C-5A Galaxy participating in the first mission of Operation Babylift crashed on approach during an emergency landing at Tan Son Nhut Air Base, South Vietnam.

In early April 1975, with much of South Vietnam overrun by communist North Vietnamese forces, the administration of U.S. President Gerald Ford began evacuating American citizens.

This first group of orphans would then transfer to charter flights and be welcomed by President Ford upon arriving in the United States in San Diego, California.

The pilot, Captain Dennis "Bud" Traynor (aged 30 at the time of the incident);[6] copilot, Captain Tilford Harp (aged 28 at the time of the incident);[7] and flight engineer, Master Sergeant Allen Engles, attempted to regain control of the airplane, and to perform a 180-degree turn in order to return to Tan Son Nhut.

The crew increased power to the engines in an attempt to arrest the descent, but despite their efforts, the plane touched down at 4:45 p.m. in a rice paddy, and skidded for a quarter of a mile (400 m), became airborne again for another half-mile (800 m), crossing the Saigon River, then hit a dike and broke up into four pieces.

Out of 314 people on board, the death toll included 78 children, 35 Defense Attaché Office employees and 11 U.S. Air Force personnel; there were 176 survivors.

[4] The accident would also "stand as the single largest loss of life" in the Defense Intelligence Agency's history until the September 11 attacks because among the crash fatalities were five DIA employees.

[14] Many of the components were looted from the crash site, thereby complicating the investigation; the U.S. Air Force paid a bounty for parts from the wreckage to recover them from the local populace.

As the air pressure differential increased with altitude, the few locks that were working correctly were unable to bear the load, and the door failed.