37 studies / 54 · Auschwitz I, Oświęcim

Auschwitz Block 11: Ill Poles in the First Mass Gassing Trial

In the cellars of Block 11, perpetrators used ill prisoners and prisoners of war as victims of the first mass trial of killing with Zyklon B at Auschwitz. They included about 250 Poles selected from the camp hospital. The museum study retains uncertainty about the exact starting date. It also describes a further dose being poured in when some of the people locked inside were still alive. [1]

Editorial account based on the sources listed below. Sources checked: 5 September 2026.

Victims and toll
About 250 Polish patients from the camp hospital and about 600 Soviet prisoners of war; the figures are approximate and the groups are distinguished.
Perpetrators
The SS at Auschwitz; the order for the first mass trial is attributed to deputy camp commander Karl Fritzsch.
Documented methods
selection of ill prisoners · confinement in underground cells · killing with Zyklon B

Basis for the facts and their qualifications: [1] [2]

Selection of the ill

The Auschwitz Museum cites the testimony of prisoner-doctor Kazimierz Hałgas. The victims were selected from the hospital without a real examination; people most exhausted were directed into a separate group. About 250 Polish patients were then placed in the basement of Block 11 together with about 600 Soviet prisoners of war. The victims must not be described collectively as Poles alone. [1]

A trial on imprisoned people

According to the museum reconstruction, the first stage probably began on 3 September 1941. Zyklon B, previously used for disinfection, was used. The order is attributed to Karl Fritzsch. When it was found the next day that some victims were still alive, another portion of the substance was added. The publication also describes the difficulty of removing and burning so many bodies. [1]

Dating and scope of the event

The IPN's educational chronology places the operation between 3 and 5 September 1941 and gives the same approximate sizes of the two main groups. This wording helps distinguish the start of the gassing from the duration of the entire operation. It does not remove the museum's cautious wording about the day of commencement. [2]

This article concerns the first mass use of Zyklon B at Auschwitz, not the entire history of killing by gas. Its inclusion in the catalogue rests on the documented selection of ill prisoners and their use in a planned trial of poison. It does not require speculation about perpetrators' emotions or the construction of a ranking of victims' suffering. [1] [2]

Limits of the findings

The exact starting date remains probable in the museum study. The numerical data are estimates. Soviet prisoners of war are not included in the Polish victim count, and this event is not added to the transport to Sonnenstein. [1] [2]

Sources and notes

Footnote markers identify the basis for specific findings. Bibliographic records remain in their original language; the notes indicate how each source is used.

The bibliographic record and source-use note are retained in Polish to preserve the original scholarly citation.

  1. opracowanie muzealne; wypowiedzi Piotra Setkiewicza i relacja Kazimierza Hałgasa. 70. rocznica pierwszego masowego użycia Cyklonu B. Państwowe Muzeum Auschwitz-Birkenau.

    opracowanie instytucjonalne · Artykuł z 3 września 2011 r.; datowanie, relacja Hałgasa i przebieg próby · Dostęp: 2026-09-05.

    Use of this source: Polscy pacjenci i jeńcy sowieccy, selekcja, Fritzsch, powtórne dodanie Cyklonu B.

  2. opracowanie edukacyjne. Auschwitz – pamięć dla przyszłości. IPN.

    opracowanie instytucjonalne · Chronologia 1941 r., wpis dotyczący 3–5 września · Dostęp: 2026-09-05.

    Use of this source: Przedział dat i rozdzielenie 250 polskich więźniów oraz około 600 jeńców sowieckich.

How we assess sources

The evidence base consists primarily of Polish scholarly publications, investigative findings, archives, museums and documented witness accounts. Reliability is assessed through the document’s provenance, scholarly method and the ability to check the finding. Statements by perpetrators and family accounts of perpetrators require especially critical comparison with other material. Two pages from the same institution may repeat one finding; they are not automatically treated as independent confirmation.

Full methodology