Served as a navigator in a B-17 Flying Fortress bomber in the Pacific during World War II. In 1945 his aircraft was sent on a secret mission over Japan to escort the new B-29 Stratofortress bombers. He was given a camera and told to photograph "anything unusual". He did see something "unusual" and shot it, and it became some of the most famous film footage ever--the mushroom cloud over Nagasaki, Japan, after the B-29s his plane was escorting dropped an atomic bomb on it.