An SS report described the scene: "The Jews stayed in the burning buildings until because of the fear of being burned alive they jumped down from the upper stories…With their bones broken, they still tried to crawl across the street into buildings which had not yet been set on fire…Despite the danger of being burned alive the Jews and bandits often preferred to return into the flames rather than risk being caught by us."
Before the war, Mengele had received doctorates in anthropology and medicine, and began a career as a researcher. He joined the Nazi Party in 1937 and the SS in 1938. He was assigned as a battalion medical officer at the start of World War II, then transferred to the Nazi concentration camps service in early 1943 and assigned to Auschwitz, where he saw the opportunity to conduct genetic research on human subjects. His subsequent experiments focused primarily on twins, with little regard for the health or safety of the victims.