Germany is building a memorial for 300,000 people murdered by the Nazis for having mental and physical disabilities or chronic illnesses.
A 30m (100ft) long glass wall is being built in the centre of Berlin, near the former site of the Nazi-era office that organised the 'euthanasia' programme.
According to the BBC, in 1939, Adolf Hitler told officials that people considered incurable should be granted a mercy killing.
The programme ended officially in 1941, but continued covertly until 1945.
Earlier, officials killed people by starving them and through lethal injection, but later used gas chambers at killing centres in Germany and Austria.
Germany's State Minister for Culture, Bernd Neumann, on Monday, said educating people about the Nazis' crimes and honouring their victims remained an obligation for the country, the report added.
