Hiroshima was the first Japanese city targeted by an atomic bomb used in war.
On August 6, 1945, the United States dropped the uranium gun-type bomb known as Little Boy over Hiroshima. The B-29 bomber Enola Gay carried the weapon, which detonated at approximately 8:15 a.m. local time. The blast devastated much of the city and caused catastrophic loss of life, with many additional deaths from injuries and radiation exposure.
Three days later, on August 9, the United States dropped the plutonium implosion bomb Fat Man on Nagasaki. Hiroshima and Nagasaki were therefore separate attacks, not two names for one event. The bombings occurred alongside the Soviet declaration of war against Japan and the Soviet invasion of Japanese-held Manchuria.
Historians continue to debate the relative importance of the atomic bombings, the Soviet intervention, Japan’s military situation, and internal political decisions in producing surrender. The Japanese government announced acceptance of the Potsdam Declaration on August 15, and the formal surrender was signed on September 2.