On Aug. 6, 1945, the Enola Gay, an American B-52 bomber, dropped the first of two atomic bombs, "Little Boy," used in WWII on the city of Hiroshima, Japan. Three days later, the US dropped the second bomb, "Fat Man," on Nagasaki to force Japan to surrender. An estimated 140,000 people died as a result of the bombing of Hiroshima, not including those who died in the years afterwards due to radiation-related illnesses. Another estimated 70,000 perished in Nagasaki.

The mushroom cloud rising above Hiroshima, shortly after "Little Boy" was dropped on Aug. 6, 1945.
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