Born in Idaho, Bleak dropped out of school to become a combat medic, and was deployed to Korea with the 40th Infantry Division. During a mission north into Chinese territory, Bleak's patrol came under heavy attack from fortified Chinese positions. Despite being wounded himself, Bleak rushed the Chinese troops multiple times and killed five of them—four using only his hands—before assisting the wounded, and shielding another soldier from a grenade blast. Bleak is credited with saving the patrol's wounded and ensuring that all of its members returned to allied lines. For these actions, he was awarded the Medal of Honor.
David Bruce Bleak was born on 27 February 1932 to William Bleak and Tamar Bleak (née Young) in Idaho Falls, Idaho, a remote farming community. The seventh of nine children, he dropped out of high school and worked for a time as a farmer and a rancher and also for railroads, but he grew dissatisfied with life in Idaho. He eventually decided to enlist in the US Army, hoping to see the world. Bleak grew to a height of 6.5 feet (2.0 m) tall and weighed 250 pounds (110 kg). He was described as humble and quiet throughout his life. Bleak was a member of the Church of Jesus Christ of Latter-day Saints.