In early 1941, almost all the Poles and Spaniards, except for a small group of specialists working in the quarry's stone mill, were transferred from Mauthausen to Gusen. Following the outbreak of the Soviet-German War in 1941, the camps started to receive a large number of Soviet POWs. Most of them were kept in huts separated from the rest of the camp. The Soviet prisoners of war were a major part of the first groups to be gassed in the newly built gas chamber in early 1942. In 1944, a large group of Hungarian and Dutch Jews, about 8,000 people altogether, was also transferred to the camp. Much like all the other large groups of prisoners that were transferred to Mauthausen and its subcamps, most of them either died as a result of the hard labour and poor conditions, or were deliberately killed.