First Lieutenant Stopa was a crew member of a B-29A Superfortress Bomber with the 28th Bomber Squadron, 19th Bomber Group. On 29 January 1953, the aircraft was shot down by MiGs eleven miles south of Pyongyang and eighteen miles east of Sariwon. He was listed as Killed in Action on 30 January 1954. His remains were not recovered. His name is inscribed on the Courts of the Missing at the Honolulu Memorial.

For his leadership and valor, First Lieutenant Stopa was awarded the Bronze Star Medal, the Air Medal with 4 Oak Leaf Clusters, the Purple Heart, 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.