Shigeaki Mori, who survived the first American atomic bomb as a boy in Japan and then spent decades as an adult researching what happened to 12 American prisoners who were killed in the attack, an effort that led to a widely photographed, tearful encounter with President Barack Obama, has died in Hiroshima, Japan. He was 88. Read more:

President Barack Obama, wearing a dark suit, hugs Shigeaki Mori, who has thin white hair and is wearing a gray suit.
Shigeaki Mori with President Barack Obama in 2016. The first American president to visit Hiroshima, Mr. Obama paid tribute to Mr. Mori, “a man who sought out families of Americans killed here, because he believed their loss was equal to his own.”Credit…

Shigeaki Mori, who survived the first American atomic bomb as a boy in Japan and then spent decades as an adult researching what happened to 12 American prisoners who were killed in the attack, an effort that led to a widely photographed, tearful encounter with President Barack Obama, died on Saturday in Hiroshima, Japan. He was 88.

His death, at a hospital, was confirmed by Barry Frechette, a filmmaker who directed “Paper Lanterns,” a 2016 documentary about Mr. Mori’s research.

Mr. Mori was an 8-year-old student on his way to school in Hiroshima when, at 8:15 a.m. on Aug. 6, 1945, an American B-29 dropped an atomic bomb over the center of the city. He was about a mile and a half from the explosion, which blew him off a small bridge into a shallow stream filled with weeds that broke his fall.

He climbed out of the water and, fearing more bombs, began to run toward the hills outside the city. Everywhere, he saw the charred and mangled bodies of people — mostly dead, but some still alive, moaning. The sky was black, and the air thick with smoke; at times, he said, he could barely see his fingers in front of his face.

“All I could do was run, run away, with tears running down my cheeks,” he said in “Paper Lanterns.”

He eventually found cover in an air-raid shelter.