In Autumn 1943, the camp administration was reorganized following a corruption scandal. By the end of 1943, the prisoner population of Auschwitz main camp, Birkenau, Monowitz and other subcamps was over 80,000: 18,437 in the main camp, 49,114 in Birkenau, and 13,288 at Monowitz where I G Farben had its synthetic rubber plant. Up to 50,000 prisoners were scattered around 51 subcamps such as Rajsko, an experimental agricultural station, and Gleiwitz, a coal mine (see The List of the Camps for a complete list of those subcamps).
The first “bunker,” with two sealed rooms, operated from January 1942 to the end of that year. The second, with four air tight rooms, became redundant in the spring of 1943, but remained standing and was used again in the autumn of 1944 when extra “capacity” was needed for the murder of Hungarian Jews and the liquidation of the ghettos. The second measured about 1.134 square feet. The victims murdered in the “bunkers” were first obliged to undress in temporary wooden barracks erected nearby. Their bodies were taken out of the gas chambers and pushed to pits where they were burned in the open.

But, in May 1944, a railroad spur line was built right into the camp to accelerate and simplify the handling of the tens of thousands of Hungarian and other Jews deported in the spring and summer of 1944. From then to November 1944, when all the other death camps had been abandoned, Birkenau surpassed all previous records for mass killing. The Hungarian deportations and the liquidation of the remaining Polish ghettos, such as Lodz, resulted in the gassing of 585,000 Jews. This period made Auschwitz-Birkenau into the most notorious killing site of all time.
Use of bunkers I and 2 stopped in spring 1943 when the new crematoria were built, although bunker 2 became operational again in May 1944 for the murder of the Hungarian Jews.[47] Crematorium II, which had been designed as a mortuary with morgues in the basement and ground-level incinerators, was converted by installing gas-tight doors, vents for the Zyklon B to be dropped into the chamber, and ventilation equipment to remove the gas thereafter.[48] It went into operation in March 1943. Crematorium III was built using the same design. Crematoria IV and V, designed from the start as gassing centers, were also constructed that spring. By June 1943, all four crematoria were operational. Most of the victims were killed using these four structures.[49]

Auschwitz-Birkenau, the largest of the concentration and extermination camps established on Polish soil, served concurrently as a labor camp and as a center for the rapid extermination of Jews. Chosen as the central location for the annihilation of the Jewish people, it was equipped with several extermination facilities and crematoria. Extermination was carried out by means of Zyklon B gas, a substance that had previously been tested on Russian prisoners of war.
Schindler moved to West Germany after the war, where he was supported by assistance payments from Jewish relief organisations. After receiving a partial reimbursement for his wartime expenses, he moved with his wife, Emilie, to Argentina, where they took up farming. When he went bankrupt in 1958, Schindler left his wife and returned to Germany, where he failed at several business ventures and relied on financial support from Schindlerjuden ("Schindler Jews")—the people whose lives he had saved during the war. He and his wife, Emilie, were named Righteous Among the Nations by the Israeli government in 1993. He died on 9 October 1974 in Hildesheim, Germany, and was buried in Jerusalem on Mount Zion, the only member of the Nazi Party to be honoured in this way.