Master Sergeant Kirkner was a veteran of World War II. In Korea, he was a member of Company B, 1st Battalion, 38th Infantry Regiment, 2nd Infantry Division. He was taken Prisoner of War while fighting the enemy near Hoengsong, South Korea, on 12 February 1951 and died while a prisoner on 30 April 1951. His remains were not recovered. His name is inscribed on the Courts of the Missing at the Honolulu Memorial.

Kirkner was awarded the Purple Heart, the Combat Infantryman's Badge, the Prisoner of War Medal, the Korean Service Medal, the United Nations Service Medal, the National Defense Service Medal, the Korean Presidential Unit Citation, the Republic of Korea War Service Medal and the World War II Victory Medal.