Kyshtym disaster

Construction of the Mayak combine lasted from 1945 to 1948.

An excerpt from the article 42 facts about Kyshtym disaster

In 1945, the construction site was selected. The route chosen was between Yekaterinburg (then Sverdlovsk) and the industrial center of Chelyabinsk. The closest major urban center at the time was the city of Kyshtym (hence the name used to describe the disaster).

Construction of the combine began in 1946. Tens of thousands of people, including Gulag prisoners or captives, were involved in the construction. The construction site was closely guarded by NKVD foremen, as the entire installation had a "top secret" classification. Most workers had no idea what they were working on.