Hiroshima was the first city attacked with a nuclear weapon in World War II.
The United States dropped the uranium bomb Little Boy on Hiroshima on 6 August 1945. The B-29 Enola Gay released the weapon at about 8:15 a.m. Japan Standard Time. The explosion destroyed much of the city and caused enormous loss of life, with deaths continuing from injuries and radiation exposure.
Hiroshima had military headquarters, communications facilities, and industrial activity, but it also contained a large civilian population. The city’s relatively flat terrain allowed the blast and fires to spread widely. The attack was the first use of a nuclear weapon in warfare and demonstrated the destructive power of the Manhattan Project.
Nagasaki became the second nuclear target three days later, on 9 August, when Fat Man was dropped after the primary target, Kokura, was obscured by cloud and smoke. Tokyo was Japan’s capital but was not the first nuclear target. The bombings, combined with Soviet entry into the war, preceded Japan’s surrender announcement and formal signing.