The United States dropped the atomic bomb on Nagasaki on August 9, 1945.
The B-29 bomber Bockscar carried the plutonium bomb known as Fat Man from Tinian in the Mariana Islands. Kokura was the primary target, but clouds and smoke obscured the city. The crew diverted to the secondary target, Nagasaki, where a brief break in the clouds allowed a visual bombing run.
Fat Man detonated at approximately 11:02 a.m. local time over the Urakami Valley, an industrial area of the city. Nagasaki’s hills limited the blast’s effects compared with the flatter terrain around Hiroshima, which had been bombed three days earlier with the uranium weapon Little Boy.
The Nagasaki bombing occurred on the same day that the Soviet Union entered the war against Japan and invaded Manchuria. Japan announced its acceptance of the Potsdam Declaration six days later, on August 15. The formal surrender followed on September 2.