The United States dropped atomic bombs on the Japanese cities of Hiroshima and Nagasaki in August 1945, during the final stage of the Second World War. The two bombings, which killed at least 129,000 people, remain the only use of nuclear weapons for warfare in history.
A uranium gun-type atomic bomb (Little Boy) was dropped on Hiroshima on August 6, 1945, followed by a plutonium implosion-type bomb (Fat Man) on the city of Nagasaki on August 9.
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. The bombings’ role in Japan’s surrender and their ethical justification are still debated.
Seventy years later, the atomic bombings in Hiroshima and Nagasaki, Red Cross hospitals are still treating thousands of survivors for the after-effects of radiation and nearly two-thirds of deaths among them are due to cancer.