Sergeant First Class Grier was a member of Company D, 1st Battalion, 24th Infantry Regiment, 25th Infantry Division. He was taken Prisoner of War while fighting the enemy in North Korea on 26 November 1950 and died while a prisoner on 21 March 1951. His remains were not recovered. His name is inscribed on the Courts of the Missing at the Honolulu Memorial.

Grier was awarded the Purple Heart, the Combat Infantryman Badge, the Prisoner of War Medal, 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.