It was during World War II that Tsutomu was an employee of the Mitsubishi Heavy Industries. During one of his work visits to Hiroshima was when the first nuclear bomb dropped in 1945. Blessed, though injured by the blast, he somehow managed to survive. He quickly returned to Nagasaki to his family and started work on the 9th of August, the day the second nuclear attack happened. He miraculously survived this too.

Later in life, Yamaguchi became a vocal proponent of nuclear disarmament. In an interview, Mr Yamaguchi said, “The reason that I hate the atomic bomb is because of what it does to the dignity of human beings.” During a telephone interview he said, “I can’t understand why the world cannot understand the agony of the nuclear bombs. How can they keep developing these weapons?” He also wrote a book about his experiences in the late 1980s.

In March 2009, Japan officially recognised Yamaguchi as a survivor of both blasts. He is now the only person officially recognised as surviving two nuclear bomb explosions.

Mr. Yamaguchi lived to a ripe old age of 93 and died on January 4th, 2010, at his home in Nagasaki.