Initially the new facilities were "underutilized". From April 1943 to March 1944, "only" 160,000 Jews were killed at Birkenau, but from March 1944 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.
The most infamous doctor at Auschwitz was Josef Mengele, the "Angel of Death", who worked in Auschwitz II from 30 May 1943, at first in the gypsy family camp. Particularly interested in performing research on identical twins, dwarfs, and those with hereditary disease, Mengele set up a kindergarten in barracks 29 and 31 for children he was experimenting on, and for all Romani children under six, where they were given better food rations. From May 1944, he would select twins and dwarfs during selection on the Judenrampe, reportedly calling for twins with "Zwillinge heraus!" ("twins step forward!"). He and other doctors (the latter prisoners) would measure the twins' body parts, photograph them, and subject them to dental, sight and hearing tests, x-rays, blood tests, surgery, and blood transfusions between them. Then he would have them killed and dissected. Kurt Heissmeyer, another German doctor and SS officer, took 20 Jewish children from Auschwitz to use in pseudoscientific medical experiments at the Neuengamme concentration camp. In April 1945, the children were killed by hanging to conceal the project.
For a better sense of reality, Spielberg originally wanted to shoot the movie completely in Polish and German using subtitles, but he eventually decided against it because he felt that it would take away from the urgency and importance of the images onscreen. According to Spielberg, “I wanted people to watch the images, not read the subtitles. There’s too much safety in reading. It would have been an excuse to take their eyes off the screen and watch something else.”
Responding with alarm to Hitler’s rise, the Jewish community sought to defend their rights as Germans. For those Jews who felt themselves fully German and who had patriotically fought in World War I, the Nazification of German society was especially painful. Zionist activity intensified. “Wear it with pride,” journalist Robert Weltsch wrote in 1933 of the Jewish identity the Nazis had so stigmatized. Religious philosopher Martin Buber led an effort at Jewish adult education, preparing the community for the long journey ahead. Rabbi Leo Baeck circulated a prayer for Yom Kippur (the Day of Atonement) in 1935 that instructed Jews on how to behave: “We bow down before God; we stand erect before man.” Yet while few, if any, could foresee its eventual outcome, the Jewish condition was increasingly perilous and was expected to worsen.
In chambers II and III, the killings took place in underground rooms, and the corpses were carried to the five ovens by an electrically operated lift. Before cremation gold teeth and any other valuables, such as rings, were removed from the corpses. In IV and V the gas chambers and ovens were on the same level, but the ovens were so poorly built and the usage was so great that they repeatedly malfunctioned and had to be abandoned. The corpses were finally burned outside, in the open, as in 1943. Jewish Sonderkommandos worked the crematoria under SS supervision.
In the spring of 1941, German conglomerate I.G. Farben established a factory in which its executives intended to exploit concentration camp labor to manufacture synthetic rubber and fuels. I.G. Farben invested more than 700 million Reichsmarks (about 2.8 million US dollars in 1941 terms) in Auschwitz III. From May 1941 until July 1942, the SS had transported prisoners from Auschwitz I to the “Buna Detachment,” at first on foot and later by rail. (Between July and October 1942 there was a pause in transports, due to a typhus epidemic and quarantine.) With the construction of Auschwitz III in the autumn of 1942, prisoners deployed at Buna lived in Auschwitz III.