Hiroshima was the Japanese city destroyed by the first atomic bomb used in war.
The United States dropped the uranium gun-type bomb Little Boy over Hiroshima on 6 August 1945. The bomb detonated at approximately 8:15 a.m. local time, devastating the city and killing or fatally injuring many people immediately and in the following months. Radiation sickness, burns, injuries, and other effects continued to cause deaths.
Hiroshima was a major military and communications center, but the attack also caused enormous civilian casualties. The bombing shocked Japan’s leadership, although it did not by itself immediately produce a unanimous decision to surrender. The Soviet Union’s entry into the war and the bombing of Nagasaki three days later also shaped the final crisis.
Hiroshima is often paired with Nagasaki in discussions of Japan’s surrender. Nagasaki was bombed on 9 August with Fat Man, a plutonium implosion weapon. Emperor Hirohito announced Japan’s surrender on 15 August, and the formal document was signed on 2 September.