The Hadamar Mental Institution where killings of disabled people took place.
At Hadamar Mental Institution, the victims were stripped, dressed in paper shirts and taken to a gas chamber where they were murdered with hydrocyanic acid gas, and the bodies moved to crematoriums by conveyer belts, six bodies to a furnace. The psychiatrist in charge at Hadamar was Dr. Adolf Wahlmann, an active member of the German Mental Hygiene Movement.
After information about the exterminations began to filter down to the German public, some members of the clergy started speaking out against the program. Hitler ordered the T4 program to stop killing patients in gas chambers. Instead the program went underground and victims were poisoned or starved to death. On May 8, 1945, the war ended in Germany. In the extermination institutes, they either kept on killing, or let the patients starve to death. As late as May 29, 1945, a four-year-old feebleminded boy was murdered in Kaufbeuren. Estimates of how many disabled people died under the Nazis range up to 250,000.
The extermination program in Nazi Germany caused eugenics theorists in the United States and Europe to backpedal on their beliefs about eliminating mental illness and congenital disabilities through euthanasia. However sterilization of people with disabilities continued to be a widespread practice well into the 1970s.