Nuclear destruction at Nagasaki, September 1945. This view is very near ground zero. On 9 August 1945, during World War II, a US bomber dropped an atomic bomb over Nagasaki, Japan. The atomic explosion, equivalent to 21,000 tons of TNT, destroyed an area several kilometres across, killing an estimated 75,000 people. This was the second atomic bomb used in warfare, following the atomic bomb over Hiroshima three days earlier. Over 220,000 people died in both cities, and tens of thousands were injured. Japan surrendered a few days later.