Private First Class Diederich was a member of Battery H, 3rd Battalion, 11th Marines, 1st Marine Division. He was killed while engaged in counter-battery fire mission north of the Imjin River, Korea, on 24 June 1952.

Diederich was awarded the Purple Heart, the Combat Action Ribbon, 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.