Atomic burst over Nagasaki. Coloured image of smoke from the atomic bomb dropped on Nagasaki, Japan, on 9th August 1945. The column of smoke is rising 18,000 metres into the air. The second atomic bomb used in military action, which was nicknamed 'Fat Man' and dropped by a US airforce B52 bomber, exploded with a force of 22 kilotons of TNT. The explosion killed 39,000 and devastated the city. The death toll continued to rise over the years as survivors developed cancers associated with radiation; ultimately claiming over 75,000 lives.