Hiroshima and Nagasaki – 1945

In August 1945 a H-29 bomber named Enola Gay after the pilot’s mother took off from Tinian Island in the Western Pacific, heading for Japan. Intensive American bombing of Japanese cities had failed to end the Pacific War, though Hiroshima Had been spared aerial bombardment. Little did the inhabitants know they were merely enjoying a stay of execution.

For Enola Gay was carrying the 4,000 kg (8,900 lb) Little Boy, the first nuclear bomb to be used in anger – and the Americans wanted to assess how effectively this untested weapon would destroy an undamaged city. This bomb derived, its explosive power from the inefficient but still deadly method of blasting two pieces of uranium together to create critical mass. The awesome detonation at (100 m (2,000 It.) above Hiroshima flattened a large area of the city and set the rest ablaze. Around 12 sq km (4.7 sq mi) vanished into a wasteland of destruction, with 70 000 inhabitants killed and as many again irradiated.

Still Japan didn’t surrender, and three days later President Harry Truman authorized the use of Fat Man on Nagasaki. The second (and final) atom bomb ever dropped was a more sophisticated plutonium weapon. This rotund device weighed 4,630 kg (10,200 lb) and was more powerful than Little Boy, but did less damage owing to Nagasaki’s hilly geography. Even so, 40,000 died and the final casualty figure would double within months. It was punishment enough. Within a week Emperor Hirohito announced Japan’s surrender and World War II was over.

Abruptly ending a war that could have taken many thousands of American lives as US forces battled across the Pacific Ocean towards Japan was President. Truman’s rationale, but the wisdom of a decision that inflicted death and terminal suffering on more than 200,000 Japanese civilians is still debated today.

When: August 6 and 9 1945

Where: Hiroshima and Nagasaki, Japan

Death toll: The two blasts and their immediate aftermath kilted 220,000 Japanese, mainly civilians (140,000 In Hiroshima and 80,000 in Nagasaki), with many hundreds more dying of radiation- related illnesses as time passed.

You should know: Japan was warned of the devastating consequences of fighting on when the Potsdam Declaration signed by Allied leaders called for immediate Japanese surrender – failing which the country would face ’prompt and utter destruction’. But in ignoring the ultimatum, the stubborn Hirohito regime can have had little idea of just how devastating that destruction could – and would – be.