8,105 tonnes of metal (of which about 7,300 tonnes of ferrous scrap metals and 805 tonnes of non-ferrous metals) and 34 million bricks salvaged. A separate search team was formed to find whatever precious items, such as money or jewellery, were left in the ruins; yet another team was working on the Umschlagplatz near street, where salvaged items were sorted and stored in warehouses. Tatiana Berenstein and Adam Rutkowski estimate the value of the pre-war houses demolished at 220 million pre-war zlotys (i.e. slightly above US$800 million in 2021 dollars), but, according to Andreas Mix, the salvaged materials were only worth 5 million reichsmarks, thus, with the initial investment of 150 million Reichsmark, the camp ran at steep losses. A couple thousand Polish civilians, who were paid, also worked in the area, as did dozens of German technicians. At one period, these people, who usually handled more sophisticated tasks, such as the maintenance of demolition machines and handling explosives, outnumbered the inmates. German constructions firms, including Berlinisches Baugeschäft (Berlin), Willy Keymer (Warsaw), Merckle (Ostrów Wielkopolski), and Ostdeutscher Tiefbau (Naumburg), operated there on contract and benefitted from slave labour provided by the prisoners. The Ostbahn railway company assisted them. Conditions The conditions in KL Warschau were extremely harsh. Prisoners' food rationing was meagre and hunger was common among the inmates, which was exacerbated by lack of food parcels from the outside, as these were not delivered to the camp. The shortages, however, were somewhat alleviated by the presence of Polish workers contracted to remove the ruins of the ghetto, as this was an opportunity for the inmates to clandestinely buy food for whatever valuables they could find in the ruins, and, in later days, when such items became scarce, for gold fillings extracted from their teeth. However, the gold contained there was also of interest of the SS guards, who strictly forbade removal of the teeth, seeking to enrich themselves by getting the precious metal after the death of the labourers. The Jews were subjected to extermination through labour. The demolition and salvage work were hard and perilous labor, carried out at a brisk pace with no regard to loss of life of the prisoners, so fatal workplace incidents were commonplace. The guards were torturing and murdering the Jews on a whim, viewing them as enemies of the state, and prisoner functionaries, particularly criminal prisoners, were hardly better in their treatment