The largest of the Auschwitz sub-camps, located in Sławięcice near Blachownia Śląska (German: Blechhammer), near the synthetic fuels plant belonging to Oberschlesische Hydrierwerke AG. It came into being in April 1944 when the Auschwitz commandant’s office took over a Schmelt Organization compulsory labor camp for Jews. The camp consisted of 25 wooden barracks—residential, storage, kitchens, washrooms, etc., surrounded by a wall of concrete panels topped with electrified barbed wire. It also had a small crematorium. Prisoners worked at expanding the plant by digging foundations and building roads and air-raid shelters. Since the American bombing of the plant started in June 1944, prisoner Kommandos were sent there as needed to locate and disarm unexploded bombs. A total of almost 200 prisoners died in the camp, and several hundred more were probably sent to Birkenau after selection. The peak population, in January 1945, was almost 4,000 men and 160 women. During the evacuation on foot to the Gross-Rosen camp, the SS shot about 800 of these prisoners. Shortly before the liberation of Blechhammer by Soviet soldiers, the SS torched, shelled, and tossed grenades into the camp barracks, in which sick prisoners had been left behind. Some of them survived.