In Nazi Germany, Adolf Hitler's T-4 "Euthanasia" Program was established in order to maintain the supposed purity (eugenics) of the so-called Aryan race by systematically killing children and adults born with physical deformities or suffering from mental illness. The name T-4 comes from the address of the office, Tiergartenstrasse 4 in Berlin. The operation was conducted still more covertly after August 1941, when 70,000 people had already died in the gas chambers of Grafeneck, Hartheim, Hadamar, Bernburg, Brandenburg and Sonnenstein. By that time every third inmate of a psychiatric institution in Germany had already died, either by being actively killed...