Second Lieutenant O'Connor was a member of Company G, 2nd Battalion, 31st Infantry Regiment, 7th Infantry Division. On 24 June 1954, he noticed that a comrade had been injured in the demilitarized zone (DMZ) by an enemy anti-personnel mine. He was attempting to rescue the victim when he accidentally set off another anti-personnel mine killing him.

Connor was awarded the Purple Heart, the Combat Infantryman's Badge, the Korean Service Medal, the United Nations Service Medal, the National Defense Service Medal and the Korean War Service Medal.