Hiroshima was the first Japanese city targeted by an atomic bomb in World War II.
The United States dropped the uranium bomb Little Boy on Hiroshima on 6 August 1945. The B-29 bomber Enola Gay carried out the mission, and the explosion devastated much of the city, killing tens of thousands of people immediately and many more from injuries and radiation effects.
Hiroshima was a major military and industrial center with an important army headquarters. It had also remained relatively undamaged by conventional bombing, which made the effects of the new weapon easier for U.S. planners to assess.
The bombing did not produce Japan’s surrender immediately. The Soviet Union declared war on Japan on 8 August, and the United States dropped a second atomic bomb on Nagasaki on 9 August. Emperor Hirohito announced Japan’s acceptance of the Potsdam Declaration on 15 August. The bombings remain subjects of historical debate, but Hiroshima was unambiguously the first city struck by an atomic weapon in wartime.