Nagasaki was the city targeted by the Fat Man atomic bomb during the final days before Japan surrendered.
The United States dropped Fat Man on Nagasaki on August 9, 1945. The plutonium implosion-type bomb was carried by the B-29 Bockscar, commanded by Major Charles Sweeney.
Kokura was the primary target for the mission, but clouds and smoke prevented the crew from making the required visual attack. Bockscar therefore proceeded to Nagasaki, the secondary target. This is why Kokura sometimes appears in accounts of the mission even though the bomb was not dropped there.
The bombing occurred on the same day that Soviet forces began their invasion of Japanese-held Manchuria. Japan announced its surrender on August 15, and its representatives signed the formal surrender instrument on September 2.