At 8:15 a.m. on Aug. 6 (2315 GMT, Aug. 5) 1945, U.S. B-29 warplane Enola Gay dropped a bomb nicknamed "Little Boy" and obliterated the southwestern city of Hiroshima, killing 140,000 of an estimated population of 350,000, with thousands more dying later of injuries and radiation-related illness.
On Aug. 9, the United States dropped another bomb, dubbed "Fat Man," about 420 kilometers (261 miles) to the south over Nagasaki, instantly killing more than 75,000 people beneath a mushroom cloud which grew as high as 9,000 meters (30,000 feet).
Japan surrendered six days later, ending World War Two.
Archive footage shows pre-bomb Hiroshima as a bustling, thriving city of trilby-topped gentlemen boarding trams, ladies dressed in elegant kimonos, and uniformed schoolchildren walking beneath cherry blossoms overhanging shopping streets.
After the blast, rubble and contorted metal stretch almost uninterruptedly to the horizon. Electricity poles and bare trees accompany the dotted handful of windowless buildings which appear to have withstood the impossible.
Japan will commemorate the 75th anniversary of the bombing of the two cities on Aug. 6 and Aug. 9 this year.
In previous years, Prime Minister Shinzo Abe and the city mayors attended annual memorial services and renewed pledges for a nuclear-free world. Bells tolled and a minute's silence was observed at the exact time the bombs detonated in both cities.Commemorations this year will be scaled back due to the COVID-19 pandemic, with fewer seats and video messages from dignitaries.