The last mass transports to arrive in Auschwitz were 60,000–70,000 Jews from the Łódź Ghetto, some 2,000 from Theresienstadt, and 8,000 from Slovakia. The last selection took place on 30 October 1944. On 1 or 2 November 1944, Heinrich Himmler ordered the SS to halt the mass murder by gas; and on 25 November he ordered that Auschwitz's gas chambers and crematoria be destroyed. The "Sonderkommando" and other prisoners began the job of dismantling the buildings and cleaning up the site. On 18 January 1945, Engelbert Marketsch, a German criminal transferred from Mauthausen, became the last prisoner to be assigned a serial number in Auschwitz, number 202499.