Question: Am Spiegelgrund was the name of a children's clinic in Vienna where 789 children were killed under the Aktion T4, was a postwar name for mass murder through involuntary euthanasia in which Nazi controlled country?
Sentence (from "Aktion T4"): Aktion T4 (German, ] ) was a postwar name for mass murder through involuntary euthanasia in Nazi Germany.
Relevant evidence: Yes