The B-29 Enola Gay bombed Hiroshima with Little Boy on 6 August 1945.
Enola Gay was commanded by Colonel Paul Tibbets of the United States Army Air Forces. The aircraft departed from Tinian in the Mariana Islands, carrying Little Boy, a uranium-based gun-type atomic bomb. The weapon exploded over Hiroshima at approximately 8:15 a.m. local time.
Hiroshima was selected as a major urban and military target. The city contained army facilities and communications infrastructure, while its relatively intact condition made the effects of the new weapon easier to assess. The blast and subsequent radiation caused enormous destruction and loss of life.
Three days later, Bockscar dropped Fat Man on Nagasaki. Kokura had been the intended primary target for that mission, but weather and visibility led the crew toward Nagasaki. The distinction between the two missions is important: Enola Gay attacked Hiroshima, while Bockscar attacked Nagasaki.