International Holocaust Remembrance Day is Jan. 27. That is the date in 1945 that Auschwitz, the network of Nazi concentration and extermination camps in occupied Poland, was liberated by the Soviet Red Army. Auschwitz had three main camps, with forced labor in each, the United States Holocaust Memorial Museum says. The complex included Auschwitz-Birkenau, an extermination camp where victims were systematically murdered. An estimated total of at least 1.1 million people died at Auschwitz between 1940 and 1945, most of them Jews, according to the museum. Six million Jews were killed in the Holocaust overall.