What did he do? I was born in ‘68 and should know this, but I don’t. Thanks.
One of the darker incidents involving the US Army in Vietnam.
http://www.history.com/topics/vietnam-war/my-lai-massacre
He was part of the crew of a Huey gunship taking part in what they thought was the clearing of a village. When they saw U.S. troops were massacring civilians, the commander of the helicopter landed it between soldiers and a group of women and children. The commander got out to confront the soldiers. He said “Y’all cover me! If these bastards open up on me or these people, you open up on them. Promise me!” Colburn, who was manning an M60, replied, “You got it boss, consider it done.”
Fortunately, that wasn’t necessary.