During the Holocaust from 1933 to 1945, over 11 million people were killed by Nazi Germany, including 6 million Jews. The Holocaust targeted not only Jews, but also Romani people (Gypsies), Slavs, communists, homosexuals, Jehovah's Witnesses, the disabled and others. At concentration camps, prisoners were classified by colored triangles sewn on their clothing. Between 200,000 to 500,000 Romani were killed - they were subjected to medical experiments and sterilization in camps. Tens of thousands died being transported in inhumane conditions in trains to camps like Auschwitz.