Only three Nazi killing centers (NS-Tötungsanstalt) were used for the gassing of the invalided prisoners: Bernburg Euthanasia Centre (manager: Irmfried Eberl), Sonnenstein Euthanasia Centre (manager: Horst Schumann), and Hartheim Euthanasia Centre (Rudolf Lonauer and Georg Renno).
Under the code name "Aktion 14f13" prisoners from Mauthausen and Gusen were murdered at Hartheim Castle starting in July 1941.

After the doctors' commissions had invalided the concentration camps' prisoners, the camp administration had to provide them on request.
They were transported either by the "Gekrat" or the Reichsbahn to one of the killing centers.
The prisoners were examined for gold teeth by a prison doctor and labelled appropriately before being led into a gas chamber, where they were killed with carbon monoxide.
After any  gold teeth were removed, for dispatch to a central office in Berlin, the corpses were incinerated in the crematorium; some corpses were examined further before incineration.

The killing was carried out by the same staff, using the same means as used previously with the mentally ill in Aktion T4.
A few administrative details were changed, in that the deaths were recorded by members of the respective camp administration; they informed relatives of the deaths, claiming illness as the cause.
A detailed description was given by Vincent Nohe to the Linz Kriminalpolizei in September 1945, who were investigating Nazi war crimes that had taken place nearby.
Nohe, who had worked as a "burner" in the crematorium at the Hartheim killing center, was convicted at the Dachau-Mauthausen Trial in 1946 and sentenced to death, for the murder of sick and incapacitated concentration camp prisoners and was executed in 1947.
Only three Nazi killing centers (NS-Tötungsanstalt) were used for the gassing of the invalided prisoners: Bernburg Euthanasia Centre (manager: Irmfried Eberl), Sonnenstein Euthanasia Centre (manager: Horst Schumann), and Hartheim Euthanasia Centre (Rudolf Lonauer and Georg Renno). Under the code name "Aktion 14f13" prisoners from Mauthausen and Gusen were murdered at Hartheim Castle starting in July 1941.
After the doctors' commissions had invalided the concentration camps' prisoners, the camp administration had to provide them on request. They were transported either by the "Gekrat" or the Reichsbahn to one of the killing centers. The prisoners were examined for gold teeth by a prison doctor and labelled appropriately before being led into a gas chamber, where they were killed with carbon monoxide. After any  gold teeth were removed, for dispatch to a central office in Berlin, the corpses were incinerated in the crematorium; some corpses were examined further before incineration.
The killing was carried out by the same staff, using the same means as used previously with the mentally ill in Aktion T4. A few administrative details were changed, in that the deaths were recorded by members of the respective camp administration; they informed relatives of the deaths, claiming illness as the cause. A detailed description was given by Vincent Nohe to the Linz Kriminalpolizei in September 1945, who were investigating Nazi war crimes that had taken place nearby. Nohe, who had worked as a "burner" in the crematorium at the Hartheim killing center, was convicted at the Dachau-Mauthausen Trial in 1946 and sentenced to death, for the murder of sick and incapacitated concentration camp prisoners and was executed in 1947.
Action 14f13