The Bombing of Dresden was an attack on the city of Dresden, the capital of the German state of Saxony, that took place in the final months of the Second World War. In four raids between 13 and 15 February 1945, 722 heavy bombers of the British Royal Air Force (RAF) and 527 of the United States Army Air Forces (USAAF) dropped more than 3,900 tons of high-explosive bombs and incendiary devices on the city. The resulting firestorm destroyed fifteen square miles (39 square kilometres) of the city centre. At least 22,000, at most 25,000 people were killed. Post-war discussion of whether or not the attacks were justified has led to the bombing becoming one of the moral causes célèbres of the Second World War.[2]