camp to work at the camp hospitals; prior to this reversal, the hospital staff comprised almost no former medical professionals. The hospitals were also used as a place to murder large groups of weakened Soviet prisoners via lethal injection. Work at the main camp centered around brick production for the first half of the war. This included the construction of a canal on the small offshoot of the Elbe river located at the campsite in order to transport raw materials from Hamburg. Inmates were forced to excavate the heavy, peaty soil with inadequate tools, regardless of weather conditions or the state of their health. Once the prisoners finished building the new brick factory in 1942, one of the most populated assignment was working in the clay pit, extracting and transporting clay from the main camp for brick production. Constructing the canal, digging the clay, and transporting the soil were known as the three "death commandos". Skilled labour was almost always given to prisoners on upper rungs of the Aryan hierarchy. From 1942 until the end of the war, armaments production became the central focus of Neuengamme, with private business ventures profiting financially from the free labour of the prisoners. Several armaments companies, including Messap, Jastram, Walter-Werke and the SS-owned Deutsche Ausrüstungswerke (DAW), established facilities inside the Neuengamme concentration camp following negotiations with the Nazi regime. Walther used their factory to manufacture Gewehr 43 semi-automatic rifles. While conditions for prisoners working in these privately owned factories were better than those working in other kommandos, all prisoners worked under the constant threat of being transferred to the death kommandos. According to the testimony of Wilhelm Bahr, an ex-medical orderly, during the trial against Bruno Tesch, 200 Russian prisoners of war were gassed by prussic acid in 1942. In April 1942, a crematorium was constructed at the camp. Prior to that all bodies were taken to Hamburg for cremation. Known death rates and population numbers Because prisoners were forced to clear the site at the end of the war, only 10% of original documentation survives from the period. From this evidence, scholars have been able to conclusively prove exact numbers for some months of the entire 1938–1945 period. It is known exactly that by the end of 1940, 2,900 were imprisoned at Neuengamme and the known death toll was over 432. In 1941, the prisoners completed the barracks, and transports arrived from Auschwitz