 During that deployment, he served as a specialist four in Company C, 1st Battalion, 5th Infantry Regiment (Mechanized), 25th Infantry Division.On February 18, 1966, in Củ Chi, Hậu Nghĩa province, his 16-man patrol was ambushed by a Viet Cong rifle company and forced to fall back.Fernández and two others volunteered to follow a sergeant back to the ambush site and rescue a wounded soldier who had been left behind.