Thursday marks seventy years since the US dropped an atomic bomb called 'Little Boy' on the Japanese city of Hiroshima, killing at least 70,000 people outright and up to 140,000 as the effects of radiation sickness took hold.
The attack was followed by the bombing of Nagasaki three days after. Six days after that, the Second World War ended. Both attacks involved huge loss of life - and remain the only time a nuclear weapon has ever been used in war.
In the wake of the anniversary Statista - using data from the Economist - looked at the most powerful nuclear weapons in the world today.