An estimated 80,000 were killed in a few seconds on August 6, 1945, when the first atom bomb, “Little Boy”, was dropped on the Japanese city of Hiroshima from a US Army Air Force B-29 Superfortress bomber, the Enola Gay. About 13 square kilometres of the city were obliterated. Two days later, the second nuclear bomb, “Fat Man”, was detonated over the Japanese city of Nagasaki.