Nagasaki was the site of the second atomic bombing on August 9, 1945.
The United States dropped the plutonium implosion weapon Fat Man over Nagasaki three days after the bombing of Hiroshima. The B-29 Bockscar carried the bomb, which detonated over the city’s Urakami Valley. The original primary target was Kokura, but cloud cover and smoke led the mission to proceed to its secondary target, Nagasaki.
Nagasaki was an important port and industrial center with shipyards, factories, and military facilities. The terrain limited some of the blast’s effects compared with a flatter city, but the destruction and loss of life were still enormous. The bombing took place on the same day that Soviet forces launched their invasion of Japanese-held Manchuria.
The two atomic bombings, the Soviet entry into the war, and Japan’s internal political debate preceded the surrender announcement. The precise weight assigned to each factor remains debated by historians, but the sequence of events is firmly established.