Shigeaki Mori, 8 years old, miraculously escaped death on the morning of Aug. 6, 1945, when the U.S. detonated an atomic bomb over Hiroshima. He was crossing a bridge when the force of the blast threw him into a river, engulfing him in darkness.

Seventy-one years later, Mori found himself in newspaper photos around the world as President Barack Obama embraced him at a ceremony held at the Hiroshima Peace Memorial on May 27, 2016.

Yards away from the eternal flame that honors the victims, Obama acknowledged Mori’s more than 30 years of research into the lives of 12 American POWs who also had perished in the bombing. Thanks to Mori’s dedicated research, their names are now included in the official register of victims.

It was the first time that a U.S. sitting president, the leader of the only nation to have used nuclear weapons in war, visited Hiroshima. The peace park memorializes the approximately 140,000 Japanese, forced laborers from Korea and other victims whose lives were lost.

The 12 U.S fliers had been captured and jailed a little more than a week before the bombing, in the city’s military police headquarters and another site. Nine men died immediately, one survived but died shortly afterward, and two others, who were in another location in the city, passed away within days from acute radiation poisoning.

Mori’s drive to uncover the airmens’ histories and contact their relatives in the U.S. was powerfully captured in a documentary, “Paper Lanterns,” directed by Barry Frechette and released in 2016. Mori’s effort to give closure to the families, and perhaps to himself, is sobering and inspiring given that Mori was so “close to the heart of the destruction,” the filmmakers write.

The film was screened last month in the Bay Area and attended by Mori and his wife, Kayoko, who traveled from Hiroshima. It will be available for streaming on iTunes and other digital platforms in August.

The recent trip was the Moris’ first visit to the U.S. Mori, 81, said at the Mountain View, Calif. screening in the Tateuchi Hall of the Community School of Music and Arts that he was overwhelmed by the friendliness of people he had met.

The couple continued to Boston and New York where the film was shown at the United Nations.

The film traces Mori’s quest to learn about the POWs, showing stacks of research materials in his home. Filmmakers visited local people who had witnessed the U.S. airmen parachute out of B-24 Liberator planes on July 28, 1945, before they were captured.

One local man had secretly kept a metal part of the airplane for 60 years. It was eventually cut into pieces and a fragment handed to a descendant of one of the deceased fliers.

The filmmaker, Frichette, became interested in the subject because his great uncle was the best friend of one of the A-bomb victims, Normand Brissette, 19, of Lowell, Mass.

Frichette interviewed descendants of the deceased airmen who expressed gratitude and wonder at Mori’s compassion and drive to find the families of people whose country had afflicted such devastation on Japan. Three days after the Hiroshima attack, a second atomic bomb was dropped on Nagasaki. Japan surrendered on Aug. 15.

Every year, on the anniversary of the nuclear attack, thousands of paper lanterns are released onto Motoyasu River near the Hiroshima Peace Museum. The lanterns symbolize wishes for peace and provide light for departed souls to find their way to the spirit world. The film is another type of memorial, illuminating Mori’s humanitarian work for peace.

It also serves as a reminder that some 3,500 Japanese Americans died in the Hiroshima bombing as a result of American family members having been caught in Japan when the war began. Their names and lives also are waiting to be remembered.