The first experimental gassing took place in September 1941, when Lagerführer Karl Fritzsch, at the instruction of Rudolf Höss, killed a group of Soviet prisoners of war by throwing Zyklon B crystals into their basement cell in block 11 of Auschwitz I. A second group of 600 Soviet prisoners of war and around 250 sick Polish prisoners was gassed on 3–5 September.[29] The morgue was later converted to a gas chamber able to hold at least 700–800 people.[30] Zyklon B was dropped into the room through slits in the ceiling.[28] In the view of Filip Müller, one of the Sonderkommando who worked in crematorium I, tens of thousands of Jews were killed there from France, Holland, Slovakia, Upper Silesia, Yugoslavia, and from the Theresienstadt, Ciechanow, and Grodno ghettos.[31] The last inmates to be gassed in Auschwitz I, in December 1942, were 300–400 members of the Auschwitz II Sonderkommando, who had been forced to dig up that camp's mass graves, thought to hold 100,000 corpses, and burn the remains.[32]

“I suddenly see Steinlauf, my friend aged almost fifty, with nude chest, scrub his neck and shoulders with little success (he has no soap) [He] sees me and asks me severely why I do not wash. Why should I wash? Would I be better off than I am? Would I please someone more? Would I live a day longer?…. Does Steinlauf not know that after half an hour with the coal sacks every difference between him and me will have disappeared?….
Oskar Schindler (28 April 1908 – 9 October 1974) was a German industrialist and a member of the Nazi Party who is credited with saving the lives of 1,200 Jews during the Holocaust by employing them in his enamelware and ammunitions factories in occupied Poland and the Protectorate of Bohemia and Moravia. He is the subject of the 1982 novel Schindler's Ark and its 1993 film adaptation, Schindler's List, which reflected his life as an opportunist initially motivated by profit, who came to show extraordinary initiative, tenacity, courage, and dedication to save the lives of his Jewish employees.