On that day, in Tay Ninh Province, South Vietnam, during Operation Toan Thang IV Petersen repeatedly exposed himself and his armored personnel carrier (APC) to enemy fire in order to protect the other soldiers of his unit.

[2] Specialist Petersen's official Medal of Honor citation reads: Specialist Petersen distinguished himself while serving as an armored personnel carrier commander with Company B during a combat operation against a North Vietnamese Army Force estimated to be of battalion size.

Petersen immediately maneuvered his armored personnel carrier to a position between the disabled vehicle and the enemy.

He placed suppressive fire on the enemy's well-fortified position, thereby enabling the crewmembers of the disabled personnel carrier to repair their vehicle.

Petersen's conspicuous gallantry and extraordinary heroism are in the highest traditions of the service and reflect great credit on him, his unit, and the U.S. Army.