Sonnenstein Euthanasia Centre

The Sonnenstein Euthanasia Clinic (German: NS-Tötungsanstalt Sonnenstein; literally "National Socialist Killing Institution Sonnenstein") was a Nazi euthanasia or extermination centre located in the former fortress of Sonnenstein Castle near Pirna in eastern Germany, where a hospital had been established in 1811.

In 1940 and 1941, the facility was used by the Nazis to exterminate around 15,000 people in a process that was labelled as euthanasia. The majority of victims were suffering from psychological disorders and intellectual disability, but their number also included inmates from the concentration camps. The institute was set up after the beginning of the Second World War as part of a Reich-wide, centrally coordinated and largely secret programme called Action T4 for the "Elimination of life unworthy of life" (Vernichtung lebensunwerten Lebens) or the killing of what the Nazis called "dead weight existences" (Ballastexistenzen). Today, the Pirna Sonnenstein Memorial Site (Gedenkstätte Pirna Sonnenstein) stands to commemorate the victims of these crimes.

The Nazi euthanasia facility at Sonnenstein Castle also supported the personnel as well as the organisational and technical preparation of the Holocaust. It was one of six that were in operation in Saxony, and was — not least due to the number of victims — one of the worst sites of Nazi war crimes in the state.

The methods of gassing prisoners at Sonnestein were later adopted at Auschwitz to exterminate the Jewish prisoners.

...
Wikipedia