Photo taken by Harold Agnew on Tinian Island in 1945. Public Domain.

Aircraft of the 509th Composite Group that took part in the Hiroshima bombing. Left to right: Big Stink, The Great Artiste, Enola Gay.

A number of participants in the World War II-era Manhattan Project — which famously set out to build an atomic bomb — went on to have important postwar academic and national defense positions in the San Diego area. Other participants later retired to the region. In 1985, on the 40th anniversary of Hiroshima, David Smollar a reporter with the Los Angeles Times interviewed several of these individuals for an article on San Diegans whose work as young scientists had helped developed nuclear weaponry. Their recollections were never written up, as the newspaper instead decided to center its anniversary coverage on a broader international retrospective. The notes remained in Smollar’s possession for the next 38 years, and the perspectives remain salient, especially given the recent release of Christopher Nolan’s film Oppenheimer.

“Geez, it really went off!”

On August 6, 1945, Harold Agnew, a graduate student in physics, rode in The Great Artiste, one of two instrumentation B-29 bombers tailing close to a third, the Enola Gay, as it dropped the atomic bomb code-named “Little Boy” on Hiroshima. Sitting in his Solana Beach home decades later, Agnew recalled, “The target was perfectly clear as we approached. I saw the bomb’s flash; it lit up the whole plane, then we were violently rocked from two sharp sound waves, reflected from the ground. So much solid dust, such a tremendous cloud, we never knew 100% where the instruments we dropped [to measure the explosive yield] were in relation to the bomb.” Agnew also took the only film of Hiroshima crumbling from overhead. “What I wrote at that moment was not all that profound, though: ‘Geez, it really went off!’”

Only 24 at the time, Agnew had come to Los Alamos, New Mexico in 1944, with physicist and later Nobel laureate Luis Alvarez, after working under Alvarez and Enrico Fermi (a 1938 Nobel recipient) at the University of Chicago on the world’s first controlled nuclear reaction. At the remote lab, he was part of the team putting together the bomb’s explosive device. “Even with all the secrecy and compartmentalization, we knew we were building some sort of weapon” — known as Project Y. “Fermi’s team was always worrying that the Germans were ahead of us. Yet in some respects, I felt like we weren’t really part of the war. A lot of my friends from high school [in Denver] had been killed already, and at Los Alamos we were well aware that the New Mexico National Guard [sent to the Philippines in mid-1941] had surrendered there in spring 1942 and been forced on the infamous Bataan Death March.”

Harold Agnew in 1945, carrying the plutonium core of the Nagasaki Fat Man bomb

Private Collection of Harold Agnew. Public Domain.

Agnew later headed Los Alamos National Laboratory from 1970-79, and then became president of GA (née General Atomics) Technologies in La Jolla through 1985. He lived in Solana Beach until his death in 2013. Did he ever regret his participation on the atomic bomb? “Are you kidding? No way! Every August 6th, I call a lot of my colleagues and we tell each other, ‘They sure as hell deserved it!’ None of this ‘sorry’ crap! You’d think the Japanese hadn’t done anything, that we just went over and blew up a town. And I have no doubts about Nagasaki either” — the location of the second atomic bombing. “It was necessary to show that it wasn’t God or the tooth fairy who had done it, and we needed to follow up right away.” Agnew believed that the several senior Manhattan Project participants who urged a demonstration of the bomb for the Japanese before any use on cities were influenced by their refugee experiences escaping from Germany and its Axis allies. ”They didn’t know anyone [in America] who was in the Pacific War; they just knew people murdered by Nazis. So after Germany’s surrender, they began to get cold feet.”

“One-hundred percent justified”

Physics professor John Clark was taken by the U.S. Army from Michigan State University to its weapons lab at Aberdeen, Maryland in 1943 because of his expertise in shaping a shock wave in an explosive for maximum effect. “They wanted the bomb’s detonation to go off within fractions of a microsecond after [the triggering device],” Clark reminisced in retirement at his La Jolla home. On the day of Hiroshima, he was in Paris, en route to interviewing captured German scientists as to the extent of their wartime nuclear weapons research. “The headlines were simple and powerful and I remember them well: ‘La Bombe Atomique.’” The following month, he was among the earliest American scientists to stand at the Hiroshima bomb’s epicenter. “The damage was unbelievable; the city was thoroughly destroyed. But at the time I felt, and I still do, that Hiroshima was one-hundred percent justified. All of us had bad feelings toward the Germans and Japanese; we thought the Japanese would fight to the last man. We had the bomb. Why not use it? As for Nagasaki, I developed second thoughts — not at the time, but much later. I think we could have held off.” In the 1950s, Clark became deputy director of the Atomic Energy Commission, and supervised more than 40 thermonuclear bomb tests, including the infamous 1954 “Castle Bravo” detonation at Bikini Atoll in the Pacific. Its deadly radiation spread to populated islands, because scientists underestimated by a factor of three the actual blast — a thousand times greater than that of “Little Boy.” Clark died in 2002.

“Very, very bright and very, very quick”

Longtime UCSD Physics Professor Hugh Bradner spent the years 1943-1945 at Los Alamos as a newly minted PhD wrestling with implosion issues in the same research area as Agnew and Alvarez. “I think most of us felt a great excitement that we were fighting a war and doing everything to support our country. As a young scientist, I was having daily interactions with others who were very, very bright and very, very quick.” He distinctly remembered having two thoughts when their theories and applications were proved successful with the July 16, 1945 test of the first nuclear device, code-named “Trinity,” in New Mexico’s remote White Sands desert. “One was, ‘Jesus! What a blast!’ And the other was, ‘Did I figure the lighting correctly’ — so the pictures would come out?’” The blast was later described as brighter than a million suns. He added, “What I am stressing is that the emotional angst at use of the bomb later expressed by so many people was not really voiced at the time, and only gradually did it become popular to wear sackcloth.” Bradner maintained his ties to military weapons research throughout his post-WWII career, and worked on high-energy physics with Alvarez at UC Berkeley until 1961 when he joined the UCSD Scripps Institution of Oceanography. He died in 2008. (Bradner also is credited with inventing the wet suit, although he ascribed it to a collaborative effort of many UC colleagues.)

“A moral problem”

William Nierenberg was an early junior-level scientist who developed misgivings even before Hiroshima. Decades later, he became the director of Scripps, but in spring 1945, he found himself a 26-year-old graduate physics student working on the bomb’s uranium isotope fuel. The work led him to compose a long statement asking that the weapon not be used on the Japanese prior to a demonstration. “I was at Oak Ridge” — the massive Tennessee facility where the fuel was being processed — “and I took the statement around to other colleagues around my age to try and drum up support to have the bomb’s destructive power exhibited somehow to the Japanese government off the country’s coast.” Unknown to Nierenberg, a similar petition was being circulated among some Manhattan Project scientists at the University of Chicago. “I knew what the bomb could do, I had seen production data. If I had been 10 years older, perhaps the statement might have had some effect. I just didn’t want the destruction — the radiation, the heat, the fire — that I knew would result. I would have liked a broader voice. I don’t say this critically. War is hell and I don’t regret my work. The use of the bomb was a hard decision [for President Harry Truman] to make. I just felt that opening this Pandora’s box was a moral problem.” He went on to a stellar postwar career in nuclear physics and oceanography, first at Berkeley and then at Scripps from 1965 to 1986. He died in 2000.

“It’s too bad it was necessary”

Herbert York, twice Chancellor of UCSD, spent his entire adult life on issues related to atomic weapons and arms control. As a Berkeley graduate student in 1943, he worked under 1939 Nobel physics laureate Ernest Lawrence on uranium enrichment and then moved to Oak Ridge, where he was billeted when word of Hiroshima came. “Someone told me, ‘They dropped a biscuit.’ My reflections at the time were not much. Our objective as younger scientists was to do our part in winning the war and Lawrence did not encourage young people to think about politics. He thought we should keep our nose to the grindstone.”

The Trinity test base camp

National Nuclear Security Administration Nevada Site Office Photo Library. Public Domain.

The soft-spoken York later became the first director of the government’s Lawrence Livermore Laboratory near San Francisco, and held numerous research and arms control roles with the government over several decades — advising on policies that very much meshed science and politics. He served as UCSD’s Chancellor from 1961 to 1964 and again from 1970 to 1972, and also taught physics. As for second thoughts about Hiroshima, York said, “When Oppenheimer [the brilliant Berkeley professor who led the Manhattan Project] later said that physicists had known sin from working on the bomb, Lawrence countered that he had never done anything that had made him know sin. Did many have concerns about the subsequent nuclear arms race with the Soviet Union? Yes. But it’s very much overstated to say there has been tremendous remorse over the bomb. Almost no one said that they wouldn’t do [their work] again if they had a second chance. What most have said, and what I have said, is that it’s too bad it was necessary, but that it was necessary. And bizarrely but true, the bomb made countries behave more conservatively after 1945 than if no bomb had been used. There might have been general war in Europe otherwise, strange as that thinking may seem. So I look back on Hiroshima not with remorse, but with regret.” York died in 2009 from the effects of cancer radiation treatment he had received two decades earlier.