Three days after Hiroshima, a B-29 bomber named Bockscar released 'Fat Man' over Nagasaki after clouds obscured the primary target of Kokura. The blast devastated the Urakami valley, killing an estimated 40,000 people immediately, with the death toll eventually reaching 70,000-80,000. Japan surrendered six days later, ending World War II.
Nagasaki was not even the primary target that morning. Bockscar's crew had circled Kokura three times, unable to see through cloud cover and smoke drifting from a firebombed neighboring city, before diverting to their secondary target with fuel running low. A brief break in the clouds over Nagasaki gave bombardier Kermit Beahan just enough of a visual fix to release the bomb.
The device, nicknamed 'Fat Man', used a plutonium core and a more complex implosion design than the uranium bomb dropped on Hiroshima. It detonated about 1,650 feet above the Urakami Valley, an area dense with factories and homes, at 11:02 AM local time. Hills that ringed the valley actually contained some of the blast, sparing parts of the city center but concentrating destruction on the industrial district.
Among the survivors was Tsutomu Yamaguchi, who had been in Hiroshima on business three days earlier and survived that bombing too, only to return home to Nagasaki in time for the second. He remains the only person officially recognized by the Japanese government as a survivor of both attacks. Japan's Supreme Council decided to surrender within days, and Emperor Hirohito announced Japan's capitulation on August 15.