Nagasaki was struck by the Fat Man atomic bomb on 9 August 1945.
The bomb was carried by the U.S. Army Air Forces B-29 Bockscar during the second wartime use of a nuclear weapon. Kokura was the mission’s primary target, but clouds and smoke obscured the aiming point. The crew therefore diverted to Nagasaki, the secondary target.
Fat Man was a plutonium implosion weapon, unlike Little Boy, the uranium gun-type bomb used against Hiroshima. It exploded at about 11:02 a.m. local time over the Urakami Valley, an industrial area in northwestern Nagasaki.
The city’s surrounding hills limited the blast’s effects compared with what might have occurred over a more exposed target. Even so, the attack caused tens of thousands of immediate deaths, with many more people dying later from injuries and radiation-related illnesses. Japan announced its acceptance of the Allied surrender terms less than a week later.