2015 is the 70th anniversary of Hiroshima, when, on 6 August at 8.15am, an atomic bob was dropped, killing one hundred thousand men, women and children in its white fury. John Hersey's spare, devastating report on the attack was first published in the New Yorker in 1946. Written in the immediate aftermath of the disaster, it chronicles what happened through the eyes of six civilians. It is a classic piece of journalism, and a defining moment of the nuclear age.