In October 1939 Hitler ordered the killing of all mentally disabled and handicapped people. This order was code named " Aktion T4". Euthanasia was first carried out on infants and children with birth defects. The decision to kill these people were made totally by the Doctors and physicians. There were no medical test done, just questionaires. From 1939 to 1945 more than 5,000 boys and girls were killed in state hospitals and clinics. Patients were sterilized and/or killed if they showed symptoms of schizophrenia, epilepsy, senile disorders, therapy resistant paralysis and syphilitic diseases, retardation, encephalitis, Huntington's chorea and other neurological conditions, and much more. A total of six killing centers were created for the disposal of these people, including the infamous Hadamar.
Buses used to transport patients to Hadamar euthanasia center. The windows were painted to prevent people from seeing the patients inside.