Nagasaki was the target of the atomic bomb code-named Fat Man on August 9, 1945.
The United States dropped Fat Man from the B-29 bomber Bockscar. The plutonium implosion weapon detonated over Nagasaki three days after Little Boy was used against Hiroshima. The Nagasaki bombing was the second wartime use of a nuclear weapon.
Kokura had been the primary target for the mission, but clouds and smoke obscured the aiming point. The aircraft therefore proceeded to its secondary target, Nagasaki, where a break in the weather allowed the crew to release the bomb.
Japan announced its acceptance of the Allied surrender terms six days later. The bombings remain subjects of historical and ethical debate, and historians also examine the Soviet Union's declaration of war and invasion of Japanese-held territory as important factors in Japan's decision.