Hiroshima was the first military target of a nuclear weapon in history.
This occurred on August 6, 1945, in the Pacific theatre of World War II, at 8:15 a.m., when the United States Army Air Forces dropped the atomic bomb "Little Boy" on the city. Most of Hiroshima was destroyed, and by the end of the year between 90,000 and 166,000 had died as a result of the blast and its effects.

Three days later, "Fat Man" (plutonium) was dropped on Nagasaki. Over the next two to four months, the effects of the atomic bombings killed 60,000 to 80,000 people in Nagasaki.