Schweres Wasser

During World War II, the Nazis developed a secret weapon named the “Schweres Wasser” (Heavy Water) which was a isotope of water that was enriched in the hydrogen isotope deuterium. This heavy water was used in the production of nuclear weapons but the allies became aware of this and they launch an operation to sabotage the heavy water production in Norway. The operation was successful and it slowed down the Nazi’s Nuclear weapon development program which in turn changed the outcome of the war.