Captain Marshall was a crew member of a B-29A Superfortress Bomber with the 343rd Bomber Squadron, 98th Bomber Wing. On 19 September 1951, while on a leaflet dropping mission, his aircraft developed engine problems and it was ditched in the Sea of Japan. He was listed as Missing in Action and was presumed dead on 29 July 1952. His remains were not recovered. His name is inscribed on the Courts of the Missing at the Honolulu Memorial.

For his leadership and valor, Captain Marshall was awarded the Distinguishes Flying Cross, 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.