Nacht und Nebel
Hesitant if not outright skeptical at first of reports coming in about the atrocities being committed by the Nazis, the Allies' doubts were pushed aside when the French entered the Natzweiler-Struthof camp (one of the "Nacht und Nebel" facilities) on 23 November 1944, and discovered a chamber where victims were hung by their wrists from hooks to accommodate the process of pumping poisonous Zyklon-B gas into the room. Keitel later testified at the Nuremberg Trials that of all the illegal orders he had carried out, the "Nacht und Nebel" decree was "the worst of all".