Seventy-five years ago, on 6 August 1945, an American warplane destroyed the city of Hiroshima with a single atomic bomb. Over the following five months, 140,000 people died. The surviving 210,000 came to be known in Japanese as hibakusha, ‘bombed people’. A second atomic bomb destroyed the city of Nagasaki on 9 August, leaving 73,000 dead and 200,000 hibakusha.