During the same period, 450 prisoners from Buchenwald and 575 prisoners from Auschwitz were gassed at the Sonnenstein Euthanasia Centre; Hartheim Euthanasia Centre was used to kill 1,000 prisoners from Mauthausen concentration camp. Between September and November 1941, 3,000 prisoners from Dachau and several thousand people from Mauthausen and neighboring Gusen concentration camp, were gassed at Hartheim. Prisoners from the Flossenbürg, Neuengamme and Ravensbrück camps were also selected and killed.