On 6 August 1945, the US dropped the first atomic bomb on the Japanese town of Hiroshima.
The allies had been firebombing Japan for weeks in an attempt to get them to surrender and put an end to the Second World War. Japanese high command was intransigent, so the decision was made to use nuclear weapons.
It would take a second bomb, on Nagasaki, to finally end the war, but the devastating effects were clear after the first.
Watch original footage of the mission and the devastation in Hiroshima in this British Pathé video, above.