When America dropped the nuclear bombs on Hiroshima and Nagasaki, the world watched as the atomic age began. The effects of the bomb were devastating and linger to this day. No government or military has ever detonated a nuclear bomb during a war since. But they have detonated them for various other reasons—including a series of tests designed to give soldiers a taste of what nuclear war might feel like.
After World War II, the UK, USSR, and US detonated more than 2,000 atomic bombs. In Britain, 20,000 soldiers witnessed atomic blasts conducted by their own government. Only a few of them are still alive today and the nuclear glow of the mushroom cloud they witnessed still haunts them. "Nuclear detonations, that was the defining point in my life," Douglas Hern, a British soldier who experienced five nuclear bomb tests, told Motherboard.
"When the flash hit you, you could see the x-rays of your hands through your closed eyes," he said. "Then the heat hit you, and that was as if someone my size had caught fire and walked through me. It was an experience that was unearthing. It was so strange. There were guys with bruises and broken legs. We couldn't believe it. To say it was frightening is an understatement. I think it all shocked us into silence."
Source: https://motherboard.vice.com/en_us/article/wjk3wb/what-does-a-nuclear-bomb-blast-feel-like
(Score: 2) by Aiwendil on Friday August 31 2018, @10:38AM
That "somehow" is due to it being one of the few concrete buildings in the center of the town at the time.
If you take a look at a picture of the area shortly after the bombing [wikipedia.org] and compare it to a fire bombing of a similar town a few months earlier [wikipedia.org] it becomes quite clear that a fire did a quite thorough job in Hiroshima.
In the picture of hiroshima, the building under the detonation point actually is wiped out, but the building across the street (the white-ish building to the left of centre of picture) survived.