<P> Unlike the other target cities, Nagasaki had not been placed off limits to bombers by the Joint Chiefs of Staff's July 3 directive, and was bombed on a small scale five times . During one of these raids on August 1, a number of conventional high - explosive bombs were dropped on the city . A few hit the shipyards and dock areas in the southwest portion of the city, and several hit the Mitsubishi Steel and Arms Works . By early August, the city was defended by the 134th Anti-Aircraft Regiment of the 4th Anti-Aircraft Division with four batteries of 7 cm (2.8 in) anti-aircraft guns and two searchlight batteries . </P> <P> In contrast to Hiroshima, almost all of the buildings were of old - fashioned Japanese construction, consisting of timber or timber - framed buildings with timber walls (with or without plaster) and tile roofs . Many of the smaller industries and business establishments were also situated in buildings of timber or other materials not designed to withstand explosions . Nagasaki had been permitted to grow for many years without conforming to any definite city zoning plan; residences were erected adjacent to factory buildings and to each other almost as closely as possible throughout the entire industrial valley . On the day of the bombing, an estimated 263,000 people were in Nagasaki, including 240,000 Japanese residents, 10,000 Korean residents, 2,500 conscripted Korean workers, 9,000 Japanese soldiers, 600 conscripted Chinese workers, and 400 Allied prisoners of war in a camp to the north of Nagasaki . </P> <P> Responsibility for the timing of the second bombing was delegated to Tibbets . Scheduled for August 11 against Kokura, the raid was moved earlier by two days to avoid a five - day period of bad weather forecast to begin on August 10 . Three bomb pre-assemblies had been transported to Tinian, labeled F - 31, F - 32, and F - 33 on their exteriors . On August 8, a dress rehearsal was conducted off Tinian by Sweeney using Bockscar as the drop airplane . Assembly F - 33 was expended testing the components and F - 31 was designated for the August 9 mission . </P> <Table> Special Mission 16, Secondary target Nagasaki, August 9, 1945 <Tr> <Td> Aircraft </Td> <Td> Pilot </Td> <Td> Call Sign </Td> <Td> Mission role </Td> </Tr> <Tr> <Td> Enola Gay </Td> <Td> Captain George W. Marquardt </Td> <Td> Dimples 82 </Td> <Td> Weather reconnaissance (Kokura) </Td> </Tr> <Tr> <Td> Laggin' Dragon </Td> <Td> Captain Charles F. McKnight </Td> <Td> Dimples 95 </Td> <Td> Weather reconnaissance (Nagasaki) </Td> </Tr> <Tr> <Td> Bockscar </Td> <Td> Major Charles W. Sweeney </Td> <Td> Dimples 77 </Td> <Td> Weapon delivery </Td> </Tr> <Tr> <Td> The Great Artiste </Td> <Td> Captain Frederick C. Bock </Td> <Td> Dimples 89 </Td> <Td> Blast measurement instrumentation </Td> </Tr> <Tr> <Td> Big Stink </Td> <Td> Major James I. Hopkins, Jr . </Td> <Td> Dimples 90 </Td> <Td> Strike observation and photography </Td> </Tr> <Tr> <Td> Full House </Td> <Td> Major Ralph R. Taylor </Td> <Td> Dimples 83 </Td> <Td> Strike spare--did not complete mission </Td> </Tr> </Table>

Original choice for the second nuclear bomb dropped on 9th august 1945