Yasuaki Yamashita moved to Mexico nearly half a century ago to try to forget about his exposure to atomic-bomb radiation, but for the past 20 years he has been speaking publicly there about his experiences.

Yamashita was 6 years old and was at his home in Nagasaki when the atomic bomb was dropped on Aug. 9, 1945, reducing much of the city to dust.

His father began to help recovering bodies the following day, but about a month later he became half paralyzed and fell into coma. He died of a brain hemorrhage a decade later, having never regained consciousness.