<P> Hiroshima was a supply and logistics base for the Japanese military . The city was a communications center, a key port for shipping, and an assembly area for troops . It was a beehive of war industry, manufacturing parts for planes and boats, for bombs, rifles, and handguns . The center of the city contained several reinforced concrete buildings and lighter structures . Outside the center, the area was congested by a dense collection of small timber workshops set among Japanese houses . A few larger industrial plants lay near the outskirts of the city . The houses were constructed of timber with tile roofs, and many of the industrial buildings were also built around timber frames . The city as a whole was highly susceptible to fire damage . It was the second largest city in Japan after Kyoto that was still undamaged by air raids, primarily because it lacked the aircraft manufacturing industry that was the XXI Bomber Command's priority target . On July 3, the Joint Chiefs of Staff placed it off limits to bombers, along with Kokura, Niigata and Kyoto . </P> <P> The population of Hiroshima had reached a peak of over 381,000 earlier in the war but prior to the atomic bombing, the population had steadily decreased because of a systematic evacuation ordered by the Japanese government . At the time of the attack, the population was approximately 340,000--350,000 . Residents wondered why Hiroshima had been spared destruction by firebombing . Some speculated that the city was to be saved for U.S. occupation headquarters, others thought perhaps their relatives in Hawaii and California had petitioned the U.S. government to avoid bombing Hiroshima . More realistic city officials had ordered buildings torn down to create long, straight firebreaks . These continued to be expanded and extended up to the morning of August 6, 1945 . </P> <P> Hiroshima was the primary target of the first nuclear bombing mission on August 6, with Kokura and Nagasaki as alternative targets . The 393d Bombardment Squadron B - 29 Enola Gay, named after Tibbets' mother and piloted by Tibbets, took off from North Field, Tinian, about six hours' flight time from Japan . Enola Gay was accompanied by two other B - 29s . The Great Artiste, commanded by Major Charles Sweeney, which carried instrumentation, and a then - nameless aircraft later called Necessary Evil, commanded by Captain George Marquardt, which served as the photography aircraft . </P> <Table> Special Mission 13, Primary target Hiroshima, August 6, 1945 <Tr> <Td> Aircraft </Td> <Td> Pilot </Td> <Td> Call Sign </Td> <Td> Mission role </Td> </Tr> <Tr> <Td> Straight Flush </Td> <Td> Major Claude R. Eatherly </Td> <Td> Dimples 85 </Td> <Td> Weather reconnaissance (Hiroshima) </Td> </Tr> <Tr> <Td> Jabit III </Td> <Td> Major John A. Wilson </Td> <Td> Dimples 71 </Td> <Td> Weather reconnaissance (Kokura) </Td> </Tr> <Tr> <Td> Full House </Td> <Td> Major Ralph R. Taylor </Td> <Td> Dimples 83 </Td> <Td> Weather reconnaissance (Nagasaki) </Td> </Tr> <Tr> <Td> Enola Gay </Td> <Td> Colonel Paul W. Tibbets </Td> <Td> Dimples 82 </Td> <Td> Weapon delivery </Td> </Tr> <Tr> <Td> The Great Artiste </Td> <Td> Major Charles W. Sweeney </Td> <Td> Dimples 89 </Td> <Td> Blast measurement instrumentation </Td> </Tr> <Tr> <Td> Necessary Evil </Td> <Td> Captain . George W. Marquardt </Td> <Td> Dimples 91 </Td> <Td> Strike observation and photography </Td> </Tr> <Tr> <Td> Top Secret </Td> <Td> Captain Charles F. McKnight </Td> <Td> Dimples 72 </Td> <Td> Strike spare--did not complete mission </Td> </Tr> </Table>

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