Sergeant First Class Byrne was a veteran of World War II. In Korea, he was a member of Battery C, 99th Field Artillery Battalion, 1st Cavalry Division. He was listed as Missing in Action while fighting the enemy near Unsan, North Korea on November 2, 1950 in support of the 8th Cavalry. He was presumed dead on December 31, 1953. His remains were not recovered. His name is inscribed on the Courts of the Missing at the Honolulu Memorial.