Besides the Jews and Slavs, countless disabled people were killed in the Holocaust.
This was the culmination of a process that began years before when the disabled were forbidden to marry, followed by compulsory sterilisation and the killing of children.
The Nazis introduced a "euthanasia program" called Aktion T4 to purify the German race by murdering the disabled.
Over 200000 blind, crippled and mentally ill people were given lethal injections (similar to the type used by modern-day killers) or gassed.
The corpse of a woman lies in an open coffin at the Hadamar Institute where she was put to death as part of the Operation T4.