Auschwitz was the largest Nazi concentration camp during World War II, where over 1 million people, mostly Jews, were killed between 1940 and 1945. The camp housed political prisoners and opponents of the Nazi regime initially, but later became a major site for the "Final Solution" and genocide of European Jews. Victims were brought by train from across German-occupied Europe and either killed immediately in gas chambers or used for forced labor before ultimately being killed. While rebellion was rare, hundreds of inmates at Auschwitz did stage an uprising in 1944 when they learned they were to be killed, killing some guards and destroying crematorium equipment before the Nazis crushed the revolt.