Caption:
Little Boy unit, the bomb that was dropped in Hiroshima, on trailer cradle in pit (note bomb bay door in upper right-hand corner). "Little Boy" was the codename for the atomic bomb dropped on Hiroshima on August 6, 1945 by the Boeing B-29 Superfortress Enola Gay, piloted by Colonel Paul Tibbets of the 393rd Bombardment Squadron of the United States Army Air Forces. It was the first atomic bomb to be used as a weapon. The second, the "Fat Man", was dropped three days later on Nagasaki.