Nagasaki was the Japanese city hit by the atomic bomb codenamed Fat Man.
The United States dropped Fat Man on Nagasaki on August 9, 1945, three days after the bombing of Hiroshima. The weapon was a plutonium implosion bomb delivered by the B-29 bomber Bockscar. It detonated at approximately 11:02 a.m. local time.
Nagasaki was not the original primary target that morning. Kokura had been designated as the main target, but cloud cover and smoke made visual bombing difficult. The aircraft shifted to Nagasaki, where a break in the weather allowed the crew to release the bomb. The city contained major industrial and military facilities, including shipbuilding works.
Fat Man caused extensive destruction and tens of thousands of deaths, though estimates vary because of immediate deaths, later radiation effects, and incomplete wartime records. The bombing occurred as Soviet forces were entering the war against Japan, creating a rapidly changing military and political crisis that preceded Japan’s surrender announcement.