With the first gas chamber in Auschwitz II operational by March 1942, the first transport of Polish Jews was sent from Silesia and Zagłębie Dąbrowskie by the Gestapo. These first Jewish prisoners were taken straight from the Oświęcim freight station to the gas chamber in Auschwitz II on or around 20 March 1942 and buried in a meadow near the gas chamber.
The newly operational gas chamber was located in bunker 1 as designated by the SS and was called the ‘’little red house’’ by the prisoners. It was a brick cottage that was transformed into a gassing facility. There were no windows since they had been bricked up. The four rooms that were once there were also converted into two insulation rooms, and on the doors was written: „Zur Desinfektion” („to disinfection”). The second brick cottage was converted and functional by June 1942, known as ‘’little white house’’ by the prisoners or as bunker 2 as per SS designation. The demonstration of mass killing in a gas chamber on a selection of Dutch Jews in bunker 2 was given to Himmler while visiting the Auschwitz concentration camp on 17 and 18 July 1942.
Bunkers I and II stopped operating in the spring of 1943 when the new crematoria were built. While bunker I was demolished in 1943 the bunker II became operational again for the extermination of the Hungarian Jews in May 1944, although it was also destroyed in November 1944. According to Piper, plans for crematoria II and crematoria III both show that they had an oven room 30 by 11.24 meters on the ground floor and an underground dressing room 49,43 by 7,93 meters, and a gas chamber which was 30 by 7 meters.
The dressing rooms consisted of wooden benches along the walls and numbered pegs for clothing. First, the victims were brought here to undress and would be afterward led through the five-yard-long narrow corridor to space where the gas chamber door opened. These chambers were white from the inside, with nozzles fixed to the ceiling resembling showerheads.
These crematoria’s daily capacity was measured in how many bodies could be burned in 24 hours. The crematorium I had a capacity of 340 corpses a day, crematoria II and III had a capacity of 1,440 each, while crematoria IV and V each had a capacity of 768. By June 1943 all four crematoria became operational while the crematorium I was closed after July 1943. This resulted in an overall capacity of 4,416 corpses in 24 hours. In addition, the Sondercommando were able to boost that capacity to 8,000 by loading three to five corpses at once. Although the maximum daily capacity was terrifying enough it was rarely needed. The average capacity was around 1000 bodies a day between 1942 and 1944.