Nagasaki was targeted by the second atomic bomb before Japan’s 1945 surrender.
The United States dropped the plutonium implosion weapon Fat Man on Nagasaki on 9 August 1945. It was the second and final wartime use of a nuclear weapon against a city. The first bomb, Little Boy, had struck Hiroshima three days earlier.
Nagasaki was not the original primary target for the mission. Kokura was designated the primary target, but cloud and smoke obscured the aiming point, so the aircraft proceeded to its secondary target, Nagasaki. Visibility conditions also affected the bombing run there.
The Nagasaki bombing occurred on the same date that Soviet forces began their offensive against Japan in Manchuria. Emperor Hirohito announced Japan’s decision to surrender on 15 August, and the formal document was signed on 2 September.