"My God, look at that son of a bitch go!" With these words of unabashed exultation, Robert Lewis, the co-pilot of Enola Gay—the B-29 aircraft that dropped the world's first atomic bomb on Hiroshima—swung away to escape the cloud mushrooming upwards. After seeing the death and destruction Little Boy unleashed, Lewis revised his reaction to: "My God, what have we done?" The director of the Manhattan Project tests, Kenneth Bainbridge, was emphatic: "We're all sons of bitches now."