The United States dropped the atomic bomb Little Boy on Hiroshima on August 6, 1945. The attack was the first use of a nuclear weapon in warfare.
The bomb was carried by the B-29 bomber Enola Gay, commanded by Colonel Paul Tibbets. It detonated over Hiroshima at approximately 8:15 a.m. local time. Hiroshima was a major military and industrial center, and the blast destroyed much of the city.
Little Boy used a gun-type uranium-235 design. Its explosion and the resulting fires killed tens of thousands of people immediately, while many more died later from injuries and radiation exposure. Exact totals remain difficult to establish because wartime records were incomplete.
The bombing was followed three days later by the atomic bombing of Nagasaki. The Soviet Union also entered the war against Japan in August, and Japan announced its acceptance of the Potsdam Declaration on August 15.