A monument to remember 300,000 Nazi victims with physical and mental disabilities or chronic illnesses has opened in Berlin.
The 24m-long blue glass wall is in front of the Berlin Philharmonie building, where the office housing the Nazi "euthanasia" programme once stood, the BBC reports.
It is the fourth monument in the German capital to victims of the Nazis.
In the past 10 years, memorials have been erected to Jewish, Roma (Gypsy) and gay victims.
Under Adolf Hitler's initial programme, the Nazis killed more than 200,000 people from early 1940 to August 1941, focusing on patients in mental health clinics and care homes.
It was known as T4, after the Tiergartenstrasse 4 office, from which it was directed.
The T4 programme continued covertly for another four years, with gas chambers and killing centres used in Germany and Austria.
It was considered a precursor to the Holocaust, in which six million Jews were murdered.