On September 3, the first pilot group of people - 600 Soviet prisoners of war and 250 other prisoners, selected among those who had fallen ill - was put to death at Auschwitz by means of Zyklon B gas. The initial attempts failed; the intended victims did not die as had been planned. They had to be taken out and made to wait until the technical flaws were corrected. Then, they were led back to the cells and killed in accordance with the plan.
