Nagasaki was the second Japanese city struck by an atomic bomb during World War II.
The United States dropped the plutonium bomb called Fat Man on Nagasaki on August 9, 1945. The attack followed the uranium bomb dropped on Hiroshima three days earlier. Nagasaki was an important industrial and military center, although cloud cover and the bomb’s aiming point meant the weapon detonated over the Urakami Valley rather than directly over the intended target area.
The bombing caused catastrophic destruction and loss of life. Japan’s leaders were also confronting the Soviet declaration of war, which occurred on the same date as the Nagasaki attack.
The combined impact of the atomic bombings, the Soviet entry into the war, and the continuing military crisis contributed to Japan’s decision to accept the Potsdam Declaration. Hirohito announced that decision on August 15.