At 2:45 A.M. on August 6, 1945, a B-29 under the command of Colonel Paul W. Tibbets, a 29-year-old veteran pilot, began to roll down a runway on Tinian Island to take off on its historic mission to Hiroshima. The plane, which Tibbets had named Enola Gay after his mother, carried a crew of twelve men and an atomic bomb fueled with uranium 235. As it flew over Iwo Jima, it was joined by two other B-29s; their crews would seek scientific information on and take photographs of the blast. Tibbets informed his crew after takeoff that the cargo they would deliver was an atomic bomb, but otherwise the flight was uneventful. The weather was clear and the Enola Gay did not encounter resistance from antiaircraft fire or enemy fighters. The fleet of just three planes caused little alarm when it appeared over Hiroshima; no warning sirens sounded and citizens saw no reason to seek shelter.
At about 8:15 A.M. (Hiroshima time) the Enola Gay’s bombardier released the bomb. It was festooned with messages that would never be read, some obscene, some wrathful; one offered “Greetings to the Emperor from the men of the Indianapolis.” Forty-three seconds after leaving the plane, the bomb exploded, proving that the uranium 235, gun-type design worked as Manhattan Project scientists had promised. Even at 30,000 feet and eleven miles from ground zero, the Enola Gay was hit by two strong shock waves that bounced it around in the air and made a noise, as one crew member recalled,