During World War II, Kassel was the headquarters for Germany's Wehrkreis IX, and a local subcamp of Dachau concentration camp provided forced labour for the Henschel facilities, which included tank production plants. The most severe bombing of Kassel in World War II destroyed 90% of the downtown area, and some 10,000 people were killed and 150,000 were made homeless. Most of the casualties were civilians or wounded soldiers recuperating in local hospitals, whereas factories survived the attack generally undamaged. Karl Gerland replaced the regional Gauleiter, Karl Weinrich, soon after the raid.