Released from B-29 Superfortress Enola Gay on August 6, 1945 at 8:15 a.m. (Japanese time), the world entered the unprecedented atomic age with the deployment of the most powerful weapon known to man.
Born from the Einstein-inspired Manhattan Project, the first nuclear weapon used in war fell for 44.4 seconds before unleashing approximately 12,500 tons of TNT over the Japanese city of Hiroshima.
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Code-named “Little Boy,” the bomb killed 140,000 people and destroyed 90 percent of the city.
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Three days later, the U.S. dropped another bomb on the Japanese city of Nagasaki, killing about 40,000 people instantly; thousands more would die of radiation poisoning.
Eight days later, Japan informally surrendered to the Allied forces, effectively ending World War II.
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This article originally appeared at Business Insider Defense. Copyright 2015. Follow BI Defense on Twitter.