The use of forced labour in Nazi Germany and throughout German-occupied Europe during World War II took place on an unprecedented scale. It was a vital part of the German economic exploitation of conquered territories. It also contributed to the mass extermination of populations in German-occupied Europe. The Nazi Germans abducted approximately 12 million people from almost twenty European countries; about two thirds of whom came from Eastern Europe. Many workers died as a result of their living conditions - mistreatment, malnutrition, and torture were the main causes of death. They became civilian casualties of shelling. At its peak the forced labourers comprised 20% of the German work force. Counting deaths and turnover, about 15 million men and women were forced labourers at one point or another during the war.