Sunao Tsuboi was on the way to his university when he was surrounded by a sharp flash. In the next breath, he was blown more than 30 feet sideways in an explosion.
It was 8:15 am on Aug. 6, 1945 when the Enola Gay dropped an atomic bomb code-named "Little Boy" over Hiroshima. The 9,000-lb. uranium bomb wreaked havoc on the western Japanese city, killing tens of thousands of people instantly. By the end of that year, around 140,000 had died as a result of the bombing.
"I found myself lying on a sidewalk, enveloped in smoke and burnt from head to toe," says Mr. Tsuboi, who was less than a mile away from ground zero. "I thought I was going to die."
After the attack, Tsuboi was unconscious for 40 days, unaware of Japan's surrender on Aug. 15. "When I heard the news, I could not believe it," he recalls. "I shouted, 'No way Japan could lose.' "
His experience as a survivor of the world's first nuclear attack moved him to become a passionate anti-nuclear activist. He hopes his story, and those of other survivors, can keep the world from seeing again what he endured.
Now a chairman of the Japan Confederation of Atomic and Hydrogen Bomb Sufferers Organizations, Tsuboi has watched Hiroshima, now a city of 1.1 million, rise phoenix-like from the ashes.
He has worked tirelessly for the abolition of nuclear weapons, lecturing at home and overseas.
But he fears that the 9/11 terrorist attacks on American cities could trigger another nuclear arms race, citing nuclear programs in Iran and North Korea.
"9/11 has changed everything," he says. "Since then, the US has even hinted at the use of nuclear weapons."
Analysts, however, argue that it is some individuals and terrorist groups, rather than states, that pose serious threats to the global order. The speculation is that if a terrorist group had a nuclear weapon, they would use it.
Here in Hiroshima, some people worry that the world will forget about the tragedy.
The number of atomic-bomb survivors fell to less than 270,000 from 323,420 in 1995, according to the groups led by Mr. Tsuboi.
"I don't believe [people will forget]," says Mr. Nobuo Kazashi, a professor of philosophy at Kobe University. Mr. Kazashi adds that while most citizens are aware of the bombing of Hiroshima and the plight of the survivors, his only concern is that "the major media downplay it."
Meanwhile, Mr. Tsuboi is trying to be optimistic. "I will...see the world change," he says.