The first man killed in the Vietnam War was murdered by a fellow airman

On June 8, 1956, U.S. Air Force Tech. Sgt. Richard Fitzgibbon died of gunshot wounds sustained in South Vietnam. He was the first casualty of what would be known to history as the Vietnam War.

Except it wasn't a Viet Cong bullet that killed Fitzgibbon — it was a fellow airman.

Fitzgibbon was assigned to the Military Assistance Advisory Group, training South Vietnamese airmen in Saigon. A crew chief, he confronted the plane's radio operator when they came under fire mid-flight, making sure the operator did his job.

After the mission, the radio operator stewed over the altercation, heading to a bar to have a few drinks and loosen up. Except he drank heavily, and the incident only intensified his anger.

Later that day, the man approached Fitzgibbon on the porch of his barracks room as he handed out candy to Vietnamese children and shot the crew chief to death.

Fitzgibbon was a Navy veteran of World War II who later joined the Air Force. His son Richard joined the Marines and fought in Vietnam. He was killed in combat near Quang Tin in 1965.

Technical Sergeant Fitzgibbon's name wasn't added to the Vietnam Memorial Wall until 1999, after a lobbying campaign from his family, with the help of Senator Ed Markey. The Department of Defense had to first change the criteria for adding a name — specifically identifying the start of the war.

The DoD now recognizes the date the MAAG was set up, Nov. 1, 1955, as the start of the conflict in Vietnam — the earliest date to qualify for having a casualty's name added to the memorial wall.

The Fitzgibbons were one of three father-son pairs who died in the Vietnam War.