On August 9, 1945, the atomic bomb code-named Fat Man was dropped on Nagasaki, Japan. It was the second nuclear weapon used in warfare, following Little Boy’s bombing of Hiroshima three days earlier.
Fat Man was carried by the American B-29 bomber Bockscar and detonated over the Urakami Valley. Nagasaki was selected as the secondary target after heavy cloud cover obscured Kokura, the primary target. The bomb used a plutonium implosion design and had a greater explosive yield than the Hiroshima weapon.
Nagasaki was an important industrial and military center, with shipbuilding, weapons production, and other wartime facilities. The mountainous terrain around the city limited some of the blast’s spread, but the destruction and loss of life were catastrophic.
A common mix-up is Tokyo, Japan’s capital, which was heavily bombed with conventional weapons but was not the city hit by Fat Man. Hiroshima was struck by Little Boy on August 6.