Tsutomu Yamaguchi may very well have been both the luckiest and most unlucky man ever.

On August 6, 1945, he was riding a small trolley across the city of Hiroshima. Yamaguchi recalls hearing the roar of an aircraft engine in the skies above during the ride, but thought nothing of it, since warplanes were constantly flying overhead during that time.

What Yamaguchi didn’t know was that this was no Japanese plane- it was the U.S. Bomber the Enola Gay, preparing to drop a 13 kiloton uranium atom bomb on the city.

Yamaguchi stepped off the tram at approximately 8:15 a.m. He looked up and saw the Enola Gay passing overhead. Then he saw two small parachutes (these chutes were attached to the warhead, though he couldn’t see the bomb itself).

Seconds later, the scene turned to chaos. Here’s Yamaguchi describing the moment of impact:

“[There was] a great flash in the sky and I was blown over.”

Yamaguchi was less than three kilometers away from the bomb when it detonated. The shock waves from the explosion ruptured his eardrums and the bright flash of light left him temporarily blinded. The heat from the warhead also seriously burned on the left side of his upper body. The last thing he remembers before passing out is seeing the mushroom cloud rising skyward.

He eventually regained consciousness, and was able to crawl his way to an air raid shelter, where he spent the night. Upon arriving at the shelter, he found his three work colleagues who had also survived the blast. All four of them were engineers from Nagasaki who had just happened to be sent to Hiroshima for work that day.

The next morning, Yamaguchi and his three colleagues left the shelter, wanting desperately to return home to try to make sense of what had just happened. On their way to the train station they passed horrific scenes of destruction, including countless charred and dying bodies.

They finally reached the station, boarded the train, and made the 180 mile journey home to Nagasaki. Yamaguchi, who was in a pretty bad state upon returning home, had his wounds tended to and bandaged as soon as he arrived back in Nagasaki.

Despite the seriousness of his injuries, Yamaguchi decided he was well enough to return to work on August 9th, just three days after the Hiroshima explosion. Upon returning, Yamaguchi recounted the tale to his boss and co-workers, who were horrified yet amazed at the same time. When he described how the bomb had melted metal and totally evaporated parts of the city, Yamaguchi’s boss Sam simply couldn’t believe it. He asked Yamaguchi,

“You’re an engineer. Calculate it. How could one bomb…destroy a whole city?”

According to Yamaguchi, it was at the exact moment that Sam asked this question (11:02 a.m.) that another blinding flash of light penetrated the room they were in: the second bomb had just been detonated in Nagasaki.

Though many people are unaware of this, the second bomb’s original target was the city of Kokura, but since Kokura was obscured by clouds that morning, the U.S. military switched the target city to Nagasaki.

Miraculously, not only did Yamaguchi survive the second blast, but so did his wife and baby son. The family spent the next week or so in an air raid shelter not far from the ruins of their home.

Yamaguchi was one of about 160 people who survived both blasts, but is the only one who was officially recognized by the Japanese government as an eniijuu hibakusha (double bomb survivor) in 2009, a year before his death.

After the war, Yamaguchi spent the rest of his life speaking out against nuclear proliferation. Speaking about his experiences a few year before passing away, Yamaguchi decribed his life as a, “path planted by God,” and said,

“It was my destiny that I experienced this twice and I am still alive to convey what happened.”

Yamaguchi finally succumbed to the radiation poisoning in his body in 2010, when he passed away from leukemia just two years after his wife died from liver and kidney cancer. He was 93 years old.

Read more from the Surviving History blog here.