"On This Date in History" Calendar
1945: US Dropped Atomic Bomb Over Hiroshima
6 August 1945: The U.S. dropped the atomic bomb on Hiroshima. A uranium gun-type atomic bomb (Little Boy) was dropped on Hiroshima on August 6th, followed by a plutonium implosion-type bomb (Fat Man) on the city of Nagasaki on August 9th. Little Boy exploded 2,000 feet above Hiroshima in a blast equal to 12-15,000 tons of TNT, destroying five square miles of the city. Within the first two to four months of the bombings, the acute effects of the atomic bombings killed 90,000–166,000 people in Hiroshima and 39,000–80,000 in Nagasaki; roughly half of the deaths in each city occurred on the first day. During the following months, large numbers died from the effect of burns, radiation sickness, and other injuries, compounded by illness and malnutrition. In both cities, most of the dead were civilians, although Hiroshima had a sizable military garrison.
On August 15, just days after the bombing of Nagasaki and the Soviet Union's declaration of war, Japan announced its surrender to the Allies. On September 2, it signed the instrument of surrender, effectively ending World War II.