Hiroshima was the first city targeted with an atomic bomb used in warfare. The United States dropped the uranium bomb Little Boy on Hiroshima on August 6, 1945.
The attack was carried out by the B-29 bomber Enola Gay, commanded by Colonel Paul Tibbets. The bomb detonated at approximately 8:15 a.m. local time, destroying much of the city and causing enormous civilian casualties.
Hiroshima was selected as a major urban and military target. It contained military headquarters, industrial facilities, and a port, while much of the city had not previously suffered the same level of conventional bombing as other Japanese cities.
Three days later, the United States dropped a second atomic bomb on Nagasaki. Japan announced its acceptance of the Allied surrender terms on August 15, although the formal surrender document was not signed until September 2.