At the Wannsee Conference on January 20, 1942, the Nazis officially decided to kill all of the Jews in Europe (11 million people). Some would be worked to death. Others would be killed in extermination camps (death camps).(). The Nazis created death camps like Auschwitz-Birkenau and Bełżec extermination camps with the goal of killing as many people as possible, as quickly as possible. These death camps replaced the "Einsatzgruppen" as the Nazis' main strategy of mass murder and genocide.