Nagasaki was struck by the second atomic bomb on August 9, 1945, days before Japan announced surrender.
The United States dropped the plutonium implosion weapon known as Fat Man over Nagasaki. The attack followed the bombing of Hiroshima three days earlier with the uranium weapon Little Boy. Nagasaki was a major industrial and military center on Kyushu, Japan’s southernmost main island.
The bombing occurred on the same day that the Soviet Union entered the war against Japan and invaded Japanese-held Manchuria. Japan’s leaders faced both developments while debating whether to accept the Potsdam Declaration. Emperor Hirohito’s recorded surrender address was broadcast on August 15.
The bombings remain among the most consequential and controversial events of the twentieth century. They caused extensive destruction and mass civilian deaths, while the Soviet entry and Japan’s internal political crisis also played important roles in the decision to surrender.