Corporal Di Maria was a medic with the Medical Company, 15th Infantry Regiment, 3rd Infantry Division. He was listed as Missing in Action while tending his wounded comrades in North Korea on 11 June 1953. He was presumed dead on 12 June 1954. His name is inscribed on the Courts of the Missing at the Honolulu Memorial.

Di Maria was awarded the Purple Heart, the Combat Medical Badge, 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.