Nagasaki was struck by the second atomic bomb on August 9, 1945.
The United States dropped the plutonium implosion bomb known as Fat Man over Nagasaki. The bomb exploded at approximately 11:02 a.m. local time. Nagasaki was the second city attacked with a nuclear weapon, following Hiroshima on August 6.
Nagasaki was not the original primary target for the mission. Kokura had been selected as the main target, but cloud cover and smoke prevented the aircraft from making the required visual identification. The bomber then proceeded to its secondary target, Nagasaki, where a break in the clouds allowed the attack.
The bombing occurred on the same day that the Soviet Union declared war on Japan and invaded Japanese-held territory in Manchuria. These events intensified the crisis that led Japan’s leaders to accept the Potsdam Declaration.