Hiroshima was the Japanese city targeted by the atomic bomb called Little Boy on August 6, 1945.
Little Boy was a uranium-based, gun-type nuclear weapon carried by the B-29 bomber Enola Gay. The aircraft dropped it at approximately 8:15 a.m. local time, producing the first use of a nuclear weapon in warfare.
The bombing destroyed much of Hiroshima and caused immense civilian loss of life. The city had been selected as a target partly because it was an important military and industrial center and had not previously experienced the same level of conventional bombing as some other Japanese cities.
Little Boy was followed by Fat Man's bombing of Nagasaki three days later. The two attacks, combined with the Soviet declaration of war and invasion of Japanese-held territory, formed the immediate background to Japan's surrender decision, though historians continue to discuss how each factor influenced the final outcome.