Nuke Honcho Who Signed Hiroshima Bomb, Filmed Blast, Dies Los Alamos director Harold Agnew helped build 75% of US' nuclear stockpile By Ruth Brown, Newser Staff Posted Oct 2, 2013 7:17 AM CDT 15 comments Comments This 1970 photo provided by the Los Alamos National Laboratory shows Norris Bradbury, left, and Harold Agnew, right—the second and third directors of Los Alamos. (AP Photo/Los Alamos National Laboratory) (Newser) – Harold Agnew, a physicist who helped build the first atomic bomb and served as a director of the Los Alamos National Laboratory, died yesterday at his home in Solana Beach, Calif. He was 92. Agnew, who was suffering from chronic lymphocytic leukemia, died while watching football on TV, the AP reports. A key figure in the nuclear age, Agnew also helped build the world's first reactor and many new weapons in the postwar period. "Harold was an innovator," says a Los Alamos historian, per the LA Times. "The vast majority of weapons in the nuclear stockpile were designed at Los Alamos and Harold had a hand in designing most of them—I'd say about 75%." Unlike many nuclear-era scientists, Agnew remained unapologetic for his contributions. He autographed the "Little Boy" bomb destined for Hiroshima, and flew in a plane alongside the Enola Gay, capturing the mushroom cloud on 16-mm film, the New York Times reports. "My feeling towards Hiroshima and the Japanese was, they bloody well deserved it," he said in a 1984 interview, per the LA Times. Agnew did, however, believe every world leader should be required to watch an atomic blast every five years ... while standing in their underwear. "We're approaching an era where there aren't any of us left that have ever seen a megaton bomb go off," he said. "And once you've seen one, it's rather sobering."