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Wrecked museum in Hiroshima
On this day:

U.S. drops atomic bomb on Hiroshima

Image: Everett Collection /

On this day in 1945, at 8:16 a.m. Japanese time, American B-29 bomber the Enola Gay drops the world's first atom bomb over the city of Hiroshima. Approximately 80,000 people were killed as a direct result of the blast, and another 35,000 were injured. At least another 60,000 would be dead by the end of the year from the effects of the fallout. U.S. President Harry S. Truman, discouraged by the Japanese response to the Potsdam Conference's demand for unconditional surrender, made the decision to use the atom bomb. The main purpose of the bomb was to force Japan to surrender and end the war for fear of further destruction.

Hiroshima was deliberately selected as it had a large urban community with military and industrial installations, and its geographical features allowed the blast of the bomb to be maximised most effectively. The Air Force agreed to stop bombing Hiroshima leading up to the dropping of the bomb so that the effects of the blast could be measured accurately. And so on 5 August, while a "conventional" bombing of the rest of Japan was under way, "Little Boy," (the nickname for one of two atom bombs available for use against Japan), was loaded onto Lt. Col. Paul W. Tibbets' plane on Tinian Island in the Marianas. Tibbets' B-29, named the Enola Gay after his mother, left the island at 2:45 a.m. on August 6. Five and a half hours later, "Little Boy" was dropped, exploding 1,900 feet over a hospital and unleashing the equivalent of 12,500 tons of TNT.

The bomb had several inscriptions scribbled on its shell, one of which read "Greetings to the Emperor from the men of the Indianapolis" (the ship that transported the bomb to the Marianas). There were 90,000 buildings in Hiroshima before the bomb was dropped; only 28,000 remained after the bombing. Over 90% of Hiroshima’s doctors and 93% of its nurses were killed. 30% of Hiroshima’s population was killed immediately, with about 30% more wounded. According to John Hersey's classic work ‘Hiroshima’ (1946), the Hiroshima city government had put hundreds of schoolgirls to work clearing fire lanes in the event of incendiary bomb attacks.

They were out in the open when the Enola Gay dropped its deadly load. There were so many spontaneous fires set as a result of the bomb that a crewman of the Enola Gay stopped trying to count them. Another crewman remarked, "It's pretty terrific. What a relief it worked." Debate after the war has centred around whether or not the dropping of the bomb on Hiroshima was necessary to win the war, with scholars and historians divided. There has also been condemnation of the second bomb dropped on Nagasaki and its necessity.