The Atomic Bomb Flashed Above Hiroshima Hiroshima is the capital of Hiroshima Prefecture, southwestern Honshu, Japan. Hiroshima has warm, humid summers with July temperatures. Hiroshima caught the attention of the world when a U.S. plane dropped the first atomic bomb on the City, destroying it on August 6,1945. The Atomic bomb blast in 1945 obliterated three- fifths of the city within seconds and killed about 75,000 people. At exactly fifteen minutes past eight in the mourning, on August 6, 1945 Japanese time, at the moment when the atomic bomb flashed above Hiroshima. At the time of the blast:Mrs.Huts Nakamura,