Beginning on 21 January 1941, Klagges started having Braunschweig's Jews deported to the concentration camps. In 1944, there were 91,000 forced labourers in the Watenstedt-Salzgitter, Braunschweig and Helmstedt area. This was far and away the highest density at labour camps anywhere in the Reich. Indeed, a great number of the people killed in the massive air raid on 15 October 1944 were forced labourers and camp inmates. When US troops occupied Braunschweig on 12 April 1945, there were still 61,000 prisoners in the camps.