 Complete the following phrase:  Chełmno Kulmhof camp was set up by SS-Sturmbannführer Herbert Lange, following his gas van experiments in the murder of 1,558 Polish prisoners of the Soldau concentration camp northeast of Chełmno nad Nerem. In October 1941, Lange toured the area looking for a suitable site for an extermination centre, and chose Chełmno on the Ner, because of the estate, with a large manor house similar to Sonnenstein, which could be used for mass admissions of prisoners with only minor modifications. Staff for the facility was selected personally by Ernst Damzog, Commander of Security Police and SD from headquarters in occupied Poznań Posen. Damzog formed the SS-Sonderkommando Lange special detachment, and appointed Herbert Lange the first camp commandant because of his experience in the mass killing of Poles from Wartheland Wielkopolska. Lange served with Einsatzgruppe VI during Operation Tannenberg. Already by mid-1940, Lange and his men were responsible for the murder of about 1,100 patients in Owińska, 2,750 patients at Kościan, 1,558 patients and 300 Poles at Działdowo, and hundreds of Poles at 