‘Living hell on earth’: Atomic bomb survivors feels duty to warn of nuclear war horrors

It is not as if Sunao Tsuboi needs another reminder of his violent encounter, as a 20-year-old university student, with a "living hell on earth". The facial scars he has carried for seven decades are proof enough. But, as if to remind himself of the day he became a witness to the horrors of nuclear warfare, he removes a black-and-white photograph and points to the shaved head of a young man looking away from the lens.

"That's me," he says. "We were hoping we would find some sort of medical help, but there was no treatment available, and no food or water. I thought I'd reached the end."

The location is Miyuki Bridge, Hiroshima, three hours after the Enola Gay, a US B-29 bomber, dropped a 15-kiloton nuclear bomb on the city on the morning of August 6, 1945. Between 60,000 and 80,000 people were killed instantly; in the months that followed the death toll rose to 140,000.

In the photo, one of only a handful of surviving images taken in Hiroshima that day, Tsuboi is sitting on the road with several other people, their gaze directed at the gutted buildings around them. To one side, police officers douse schoolchildren with cooking oil to help soothe the pain of their burns. "People like me are losing the strength to talk about their experiences and continue the campaign against nuclear weapons," says Tsuboi, a retired school principal who has travelled the world to warn of the horrors of nuclear warfare.

The average age of the 183,000 registered survivors of the Hiroshima and Nagasaki attacks rose just above 80 for the first time last month.

While each has a unique memory of the morning of August 6 and its aftermath, near disbelief at the scale of destruction is a theme that runs through the testimony of (atomic bomb survivors).