At The History Place, a description of Nazi euthanasia practices.

In the fall of 1939 the German government established, under the Reich Chancellery, the Euthanasie Programme under the direction of Philip Bouhler and Dr. Karl Brandt. The headquarters of the operation were at Tiergartenstrasse 4, Berlin and the code name for the program was derived from that address -- T-4. The choice of terminology for the program is consistent with the Nazis' penchant for ...

T4 Medical Killing Program The camouflage organization created for the medical killing of adults was known as the Reich Work Group of Sanatoriums and Nursing Homes (Reichsarbeitsgemeinschaft Heil- und Pflegeanstalten, or RAG). It operated from the Berlin Chancellery, at Tiergarten 4, hence the T4 code name. In time, word of the Nazi T4 program (medical killing on a vast scale) filtered down into ...