Private First Class Brumagen was a member of Company F, 2nd Battalion, 7th Cavalry Regiment, 1st Cavalry Division. He was seriously wounded by the enemy in South Korea on 31 July 1950 and returned to duty on 19 August 1950. He was Killed in Action while fighting the enemy in South Korea on 1 September 1950.

Brumagen was awarded the Purple Heart with Oak Leaf Cluster, the Combat Infantryman 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.