Just a detail. According to the latest research, the demolition was organised by Colonel Boris Epin (representative of the General Staff, military engineer). NKVD regiment provided security at the station. Ironically, in the following chaos, Colonel Epin was detained immediately after the operation and kept for 10 days under arrest.It is reported that the NKVD team used almost 20 tons of explosives to tear a 165-meter-long breach in the dam.