At dawn, Friday, August 30, 1968, I woke inside my cockroach-infested hooch at LZ Betty, sixteen miles south of the Demilitarized Zone, to go on my twenty-second and last patrol. I was the sergeant and team leader of a five-man long-range reconnaissance patrol (LRRP, or “Lurp”) assigned to the First Cavalry Division’s First Brigade, whose area of operation was from Quang Tri City, near the coast of South Vietnam, to the heavily forested mountains out west, halfway to Laos.

A crater is a typically bowl-shaped depression in the ground caused by a sudden, violent release of energy. And the result of that sudden energetic event is often the loss of lives in the immediate area. More rarely, a crater saves a life. One such crater, in Quang Tri Province, Vietnam, US Army Corps of Engineers grid coordinates 317448, saved five young American soldiers. It also helped advance my understanding and appreciation of physics