One of the Allies’ greatest fears during World War II was that Adolf Hitler and his Nazi forces would unleash what is called Wunderwaffen, or “miracle weapons”. Some of the rumored weapons were bizarre, such as the earthquake generators and the death rays. But others, such as bacterial weapons, rockets and deadly new gases, were entirely achievable. The most disturbing? The possibility that the Germans could make – and detonate – an atomic bomb.
At the start of World War II, Germany far surpassed other countries in atomic research. In 1938, German scientists discovered nuclear fission. The Germans even organized a special scientific unit led by quantum physicist Werner Karl Heisenberg to develop an atomic weapon, amassing stocks of uranium for the effort.
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To learn the truth, the Americans organized a secret special operations unit in 1943, tasked with discovering Nazi nuclear secrets and capturing their best scientists. Nicknamed the Alsos Mission, and nicknamed “Lightning A”, the unit was composed of a small force of scientists and counterintelligence troops, led by Colonel Boris T. Pash. A counterintelligence officer who had led the security of the United States’ own nuclear weapons efforts, the Manhattan Project, Pash had discovered a circle of communist spies trying to steal American nuclear secrets.
Colonel Pash and his team initially followed the Allies to the front lines of Italy and France, interrogating scientists and capturing research. These efforts led American intelligence to conclude that Germany do not have the ability to develop a nuclear weapon. But they had no evidence, and with the world already beginning to evolve towards a dead end of the Cold War between the Soviet Union and the United States, the Americans were doubly concerned that nuclear research and German scientists would not fall in the hands of the communists.
To prevent this from happening, Pash led Lightning A on his most dangerous and daring operation to date: across enemy lines and into Germany.
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“Operation Big”: Unearthing the Nazi Nuclear Laboratory
When the small force of Pash entered enemy territory on April 22, 1945, during an operation called “Operation Big”, they were only protected by two armored cars, four Jeeps equipped with machine gun supports and a cache of German weapons captured. Even if the Nazi regime collapsed, the unit faced threats of resistance from military units and so-called Wehrwulf, or bands of “werewolves” of young hard-core Nazis.
A replica of the Allied nuclear reactor test facility now located at the Atomkeller Museum in Haigerloch, Germany.
Michael Latz / DAPD / AP Photo
Working before advancing the Allied armies, Lightning A traversed the countryside around Heidelberg, heading south to the town of Haigerloch. Luckily for Pash, the city’s Germans, believing that the war would soon be over, surrendered to the small group of Americans, hanging white sheets on the windows and poles.
In a cave not far from Haigerloch, Colonel Pash found the price: a Nazi nuclear laboratory equipped with a test reactor. The Americans began to dismantle it the next day, and then destroyed the site. Pash then divided his team in an effort to track down the hiding German scientists. A Lightning A unit arrived in Tailfingen, barely escaping an attack by a Wehrwulf bandaged. The other descended on Bisingen, where despite the attack by the locals, they controlled the city.
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Dredging a sump for nuclear secrets
On April 24, the Pash team made another major discovery: a textile factory and surrounding buildings that had been turned into a laboratory for German nuclear research efforts. There they gathered 25 scientists. Through interrogations, they learned that the German research files had not been destroyed as scientists had claimed before, but that they were sealed inside a sealed drum that they had sunk in a sump.
Pash delegated the disgusting job of recovering the documents to subordinates who, after struggling with human waste, managed to recover the drum. He also found the pile of Nazi uranium and heavy water (a form of water that contains more than normal amounts of hydrogen) buried in a nearby field. They even located Heisenberg’s office – but the scientist was long gone. A week earlier, he had fled by train and bicycle to join his family in the mountains of Bavaria, nearly 200 miles away.
Werner Karl Heisenberg, a Nobel Prize winner who later became a key figure in Hitler’s atomic project.
Corbis / Getty Images
In search of the best physicist
Operation Big has ended, but Pash wanted Heisenberg. Following the clues and full of forebodings – there were still nagging rumors that the Fuhrer would release one last Wunderwaffe against the Allies – Pash headed for the Bavarian Alps. After Wehrwulf the youths sabotaged a critical bridge over a gorge, the Lightning A team had to abandon their vehicles, after which Pash led his 19 men across the ravine and into the mountains.
When they arrived in the town of Urfeld, near the alpine lake of Walchen, they found Germans going to them en masse—About 700 SS soldiers give way to its meager pass of soldiers. Thanks to a little chicane, Pash led the Germans to believe that his strength was greater than it was and bluffed his way out of the precarious situation. He was not interested in returning the soldiers – he was there for Heisenberg. After interrogating locals, Pash found the scientist and his family in a mountain hut on May 2, 1945. Two days earlier, Hitler had committed suicide in his bunker.
German scientists were finally brought to a safe house called Farm Hall in England. Scientists, for their part, have publicly declared that they are anti-Nazis and that they have tried passively-aggressively to undermine the research so that Hitler could not get the bomb. Secretly, British intelligence tapped Farm Hall and learned that scientists were surprised that the Americans had successfully detonated an atomic bomb in Hiroshima. Otto Hahn, who had discovered nuclear fission, was anti-Nazi and did not participate in German atomic research efforts, felt personally responsible that his first discoveries had led to so many horrible deaths. And while the Americans could not conclusively infer the motivations of other scientists, it was clear that in the end, Germany was not close to developing a functional atomic bomb.
More information on the remarkable Alsos mission is revealed as the source material is declassified and digitized. Colonel Pash’s documents, held at the Hoover Institution Library and Archives in Stanford, California, contain a wealth of information on this daring episode in military history, including an annotated map created by Pash, a newspaper, and footage of the daring Alsos mission.
Joseph A. Williams is the author of Sunken gold: a story from the First World War, espionage and the greatest treasure rescue in history and Seventeen Fathoms Deep: the saga of the S-4 submarine disaster.
