Although the SS oversaw the killings at each gas chamber, the bulk of the work was done by prisoners known from 1942 as the "Sonderkommando" (special squad). These were mostly Jews but they included groups such as Soviet POWs. In 1940–1941 when there was one gas chamber, there were 20 such prisoners, in late 1943 there were 400, and by 1944 during the Holocaust in Hungary the number had risen to 874. The "Sonderkommando" removed goods and corpses from the incoming trains, guided victims to the dressing rooms and gas chambers, removed their bodies afterwards, and took their jewelry, hair, dental work, and any precious metals from their teeth, all of which was sent to Germany. Once the bodies were stripped of anything valuable, the "Sonderkommando" burned them in the crematoria.