Hiroshima was struck by the atomic bomb nicknamed Little Boy on August 6, 1945. The United States dropped the uranium-235 weapon from the B-29 bomber Enola Gay.
The bomb detonated at approximately 8:15 a.m. local time. Hiroshima was a military and industrial center, and the explosion destroyed much of the city while causing enormous civilian casualties. Many more people later died from injuries and radiation-related illness.
Little Boy was the first nuclear weapon used in warfare. Its destruction became one factor in Japan’s surrender debate, although historians continue to discuss how the bombings, the Soviet declaration of war, blockade, military pressure, and internal Japanese politics interacted.
A second atomic bomb, Fat Man, was dropped on Nagasaki three days later. Japan announced acceptance of the surrender terms on August 15 and signed the formal instrument on September 2.