US Army Air Force

Nagasaki Bomb Exploding, 9 August,1945

U.S. Department of Energy

At 11:02 a.m., 9 August, 1945, at an altitude of 1,650 feet, Fat Man exploded over Nagasaki. The yield of the explosion was later estimated at 21 kilotons, 40 percent greater than that of the Hiroshima bomb. Nagasaki was an industrial center and major port on the western coast of Kyushu. As had happened at Hiroshima, the "all-clear" from an early morning air raid alert had long been given by the time the B-29 had begun its bombing run. A small conventional raid on Nagasaki on August 1st had resulted in a partial evacuation of the city, especially of school children. There were still almost 200,000 people in the city below the bomb when it exploded. The hurriedly-targeted weapon ended up detonating almost exactly between two of the principal targets in the city, the Mitsubishi Steel and Arms Works to the south, and the Mitsubishi-Urakami Torpedo Works (right) to the north. Had the bomb exploded farther south the residential and commercial heart of the city would have suffered much greater damage. texag57