Nagasaki was hit by the second atomic bomb used in warfare on 9 August 1945.
The United States dropped the plutonium implosion bomb Fat Man from the B-29 bomber Bockscar. The original target was Kokura, but cloud cover and smoke prevented the crew from identifying the aiming point. The aircraft turned toward its secondary target, Nagasaki, where the bomb was released.
Nagasaki contained important shipbuilding and industrial facilities, but the city’s mountainous terrain affected the blast pattern. The bombing caused enormous destruction and loss of life, though casualty estimates vary because of incomplete wartime records and later deaths from injuries and radiation exposure.
The bombing followed the attack on Hiroshima three days earlier. On the same date, the Soviet Union began its offensive against Japanese forces in Manchuria after declaring war. Japan’s leaders then moved toward accepting the Potsdam Declaration. Hirohito announced the decision on 15 August, and the formal surrender was signed in Tokyo Bay on 2 September.