It was September 9, 1945, and Lt. Daniel McGovern, a US Army Air Force cameraman, was recording ground zero, the spot directly below the bomb explosion four weeks earlier. Few would recognize McGovern, but the vision of the apocalypse is familiar from the Hiroshima and Nagasaki documentary at the end of World War II. The footage will be shown again this week and next for the 77th anniversary of the atomic bombings that destroyed Japanese cities and showed the reality of nuclear war: blasted landscapes, charred skeletons, radiation sickness. But these shocking images might not have existed if it weren’t for McGovern. As part of the US Strategic Bombing Survey – which studied the impact of the bombings – McGovern oversaw Japanese and US camera crews in Hiroshima and Nagasaki. Back in the US, he saved the video from suppression by making secret copies. McGovern holding his Nagasaki photo with his son Tim in 1998. Photo: Al Schaben/Los Angeles Times/Getty Images Only now, decades later, has his full story emerged. Joe McCabe, a journalist from McGovern’s native County Monaghan, Ireland, compiled his remarkable life into a biography, Rebels to Reels, published earlier this month after 20 years of research, including interviews with McGovern before his death in 2005. McGovern’s relatives traveled to Monaghan last week for the unveiling of a plaque. “I’m overwhelmed. It’s such a surprise to see my uncle Dan and his family being recognized,” said Michael McGovern, a nephew. The investigation revealed that McGovern witnessed not only the dawn of the atomic age, but also the Irish Revolution, Franklin Roosevelt’s White House, wartime Hollywood, and the so-called Roswell incident that entered UFO lore. His presence at key moments in the 20th century has drawn comparisons to Forrest Gump, the fictional character who stumbled into historical events. “Dan was the most interesting person I’ve ever met,” McCabe said. McGovern was born in Monaghan in 1905, the son of a policeman. During the 1919-21 Irish War of Independence, still a boy, he rode with the Black and Tan, a British military force. The family moved to the US and McGovern, nicknamed Big Mack for his 6ft 5in frame, joined the Air Force, ending up in its art wing, the First Motion Picture Unit. He was a photographer for President Roosevelt before establishing an Air Force camera training school in Hollywood, where he met Ronald Reagan, Clark Gable and other stars. McGovern flew bombing missions over Germany – surviving two crashes – and shot footage used in a 1944 documentary, The Memphis Belle: A Story of a Flying Fortress. His defining work came in Japan a year later, where he photographed and filmed on 35mm in black and white and Technicolor. The fields around Nagasaki were bleached and the city looked as if it had been flattened by a “huge anvil,” he later told McCabe. In a ruined school he filmed the corpses of children among piles of skulls. “Hundreds of children had been absorbed by the windows. We always found bones.” He filmed terrifying scenes in overwhelmed hospitals, including the agony of a 16-year-old boy named Sumiteru Taniguchi. “His whole back looked like a bowl of bloated tomatoes.” Other patients had rashes, hair loss and bleeding from the nose and mouth – a mysterious illness later identified as radiation sickness. McGovern also documented the phenomenon of people being vaporized but leaving shadows caused by the radiant heat. The two atomic bombs are estimated to have killed more than 200,000 people. McGovern’s teams collected 100,000 feet of color footage and enlisted the help of a Japanese news agency, Nippon Eigasha, which had 26,000 feet of black-and-white footage long before the Americans arrived. The Irishman helped edit the Japanese footage into a documentary called Effects of the Atomic Bomb on Hiroshima and Nagasaki and planned to convert the color footage into another. Authorities in Washington, however, classified the footage as secret in 1946. “They didn’t want the American public to see the horror,” McGovern said. He discreetly made copies at the Pentagon. He stored one set at an air force film depot in Dayton, Ohio, and kept another set himself. Years passed – McGovern witnessed missile tests and dismissed alien theories at Roswell as “a load of crap” – and then in 1967 a US congressional committee that included Robert Kennedy asked to see the atomic bomb material. The material was declassified but no one could find the originals. McGovern, now a lieutenant colonel, directed authorities to his copies. In 1970 the general public got their first glimpse of some of the footage. It was incorporated into a film called Hiroshima Nagasaki – August 1945 which premiered at the Museum of Modern Art in New York. The hall was packed. In the end no one made a sound.