When Harry Truman learned of the success of the Manhattan Project, he knew he was faced with a decision of unprecedented gravity. The capacity to end the war with Japan was in his hands, but it would involve unleashing the most terrible weapon ever known. For Truman, the choice whether or not to use the atomic bomb was the most difficult decision of his life. On August 6, 1945, a plane called the ENOLA GAY dropped an atomic bomb on the city of HIROSHIMA. Instantly, 70,000 Japanese citizens were vaporized. In the months and years that followed, an additional 100,000 perished from burns and radiation sickness.