Sergeant Fallis was a member of Company L, 3rd Battalion, 5th Cavalry Regiment, 1st Cavalry Division. He was taken Prisoner of War while fighting the enemy in South Korea on 15 February 1951 and died while a prisoner on 31 March 1951. His remains were not recovered. His name is inscribed on the Courts of the Missing at the Honolulu Memorial.

Fallis was awarded the Combat Infantryman 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 and the Republic of Korea War Service Medal.