General panoramic view of Hiroshima after the bomb shows the devastation about 0.4 miles. Hiroshima, Japan. On August 6, 1945, a single nuclear bomb (nicknamed "Little Boy") was dropped on Hiroshima, destroying almost all of the city's houses and buildings and instantly killing 80,000 people. The death toll continued to rise over the years, as survivors contracted cancers associated with radiation; ultimately the bomb claimed over 200,000 lives.