First Lieutenant Dees was the pilot of a F-84E Thunderjet fighter with the 430th Fighter-Bomber Squadron, 474th Fighter-Bomber Group. On 9 October 1952, while on a combat mission at the railroad yards at Sinyang, North Korea and as he delivered his bombs, his aircraft received a direct hit by anti-aircraft fire and augured into the ground. He was listed as Missing in Action.

His remains were recovered on 9 November 1954 and identified on 21 December 2010. His name is inscribed on the Courts of the Missing at the Honolulu Memorial.

Dees was awarded the Air Medal, 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.