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    Auschwitz-Birkenau Gas Chambers: Holes in Gas Chamber Roofs

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    Were there holes for Zyklon-B in the gas chamber roofs at Auschwitz-Birkenau?  

    Holocaust deniers claim:

    Zyklon-B was supposedly poured into the gas chambers at Auschwitz-Birkenau through holes in the roofs. No holes have ever been found in the gas chamber roofs. If there were no holes in the roofs, then the rooms were not gas chambers and Auschwitz-Birkenau was not an extermination camp.

    No holes, no Holocaust!” said David Irving. Irving, who the High Court in London declared to be a Holocaust denier, racist, and antisemite, advanced this slogan in his libel suit against historian Deborah Lipstadt. During his cross-examination of Professor Robert Jan van Pelt, who wrote the expert witness report on Auschwitz-Birkenau, Irving asked: “And you do accept . . . if you were to go to Auschwitz the day after tomorrow with a trowel and clean away the gravel [from the ruins of Cremas/Gas Chambers 2 or 3] and find a reinforced concrete hole . . . this would make an open and shut case and I would happily abandon my action immediately?”[1] To Irving, the holes in the gas chamber roofs are critically important. Similarly, Robert Faurisson, a French Holocaust denier, asked about Gas Chamber 2 at Birkenau: “The caved-in roof of this supposed mass extermination ‘gas chamber’ has visibly never had any of the four special holes . . . through which, we are told, Zyklon B pellets were poured in. This being the case, how, simply, could an execution gassing operation have even begun here at Birkenau, the core of the so-called ‘Holocaust’?”[2]

    The facts are:

    Holocaust deniers are clearly wrong. Photographs and eyewitness testimony, from both perpetrators and survivors, testify to the existence of holes in the gas chamber roofs. Further, a rigorous forensic study in 2000 has located and proved beyond doubt that they existed.

    What is Zyklon-B?

    Zyklon-B is the product name for the blue-green chalk pellets which were soaked with a liquid pesticide called hydrogen cyanide (HCN). The chalk pellets are kept in vacuum-sealed cans. When they are exposed to the air, the poisonous HCN gas is released. After the HCN disperses into the air, only the inert and harmless pellets are left to be collected and disposed of later.

    Zyklon-B Pellets. Goku122 at the Polish language Wikipedia [GFDL (http://www.gnu.org/copyleft/fdl.html) or CC-BY-SA-3.0 (http://creativecommons.org/licenses/by-sa/3.0/)], via Wikimedia Commons.
    Zyklon-B Pellets. Goku122 at the Polish language Wikipedia [GFDL (http://www.gnu.org/copyleft/fdl.html) or CC-BY-SA-3.0 (http://creativecommons.org/licenses/by-sa/3.0/)], via Wikimedia Commons.

    What are the holes in the roofs of the gas chambers?

    The morgue room in Crema/Gas Chamber 1 of the Main Camp was turned into a gas chamber in September 1941. The doors were made air-tight and holes were cut in the roof and capped with wooden chimneys. Crema/Gas Chamber 1 became a test facility for the new method of using Zyklon-B to murder large numbers of human beings at one time. When the method of pouring Zyklon-B through holes in the roof proved to be successful, the design was implemented in Cremas/Gas Chambers 2 and 3 at Auschwitz-Birkenau.

    When Heinrich Himmler, the Reichsführer of the SS, ordered that Auschwitz-Birkenau was to become an extermination center, Cremas 2 and 3 were in the process of being built. In both buildings (which are identical), two underground rooms, originally designed to be morgues, were adapted to become an undressing room and a gas chamber room. On the flat concrete roofs of the ex-morgue rooms, the Germans cut four holes over which they built a small chimney, which was covered with a gas-tight lid. It was through these holes on the roofs that the Zyklon-B was dropped into the gas chambers.[3]

    Eyewitness evidence on the existence and use of the holes:

    There are multiple survivor eyewitnesses who described the pouring of Zyklon-B through the small chimneys on the roofs.

    Filip Müller, a Slovak Jew who arrived in Auschwitz-Birkenau in April 1942, was put to work in Cremas/Gas Chambers 2 and 3. He recalled the gas chamber room as a long, oblong room with an unusually low ceiling and whitewashed walls. He described the columns below the holes in the roof: “Down the length of the room concrete pillars supported the ceiling. However, not all the pillars served this purpose: for there were others, too. The Zyclon-B gas crystals were inserted through openings into hollow pillars made of sheet metal.” Müller also witnessed the process of inserting the Zyklon-B into the gas chambers from the outside of the building: “The vehicle stopped alongside the lawn behind the crematorium where the concrete shafts projected, through which the pea-sized grains of Zyclon B gas were introduced. Nearby the two ‘disinfecting operators’ were ready and waiting for their orders to pour in the gas crystals.”[4]

    Shlomo Venezia, a Greek Jew who arrived in Auschwitz-Birkenau in April 1944, was put to work in the cremas/gas chambers. He recalled: “. . . the German bringing the gas would arrive. It took two prisoners from the Sonderkommando to help him lift up the external trapdoor, above the gas chamber, then he introduced Zyklon B through the opening. The lid was made of very heavy cement . . . The cover was just opened, the gas thrown in, and the cover closed again.”[5]

    Henryk Tauber, a Polish Jew who arrived at Auschwitz-Birkenau on January 19, 1943, was assigned to the Sonderkommando in Crema/Gas Chamber 2 in Birkenau. He recalled interior pillars made of heavy wire-mesh “which went up through the roof.” Through the window of the incineration room he observed the process of introducing the Zyklon-B: “Each transport was followed by a vehicle with Red Cross markings which entered the yard of the crematorium . . . They took the cans of Zyklon from the car and put them beside the small chimneys used to introduce the Zyklon into the gas chamber. There, Scheimetz opened them with a special cold chisel and hammer, then poured the contents into the gas chamber. Then he closed the orifice with a concrete cover.”[6]

    Photographic evidence that testifies to the existence of holes:

    In the fall of 1944, Allied planes flew reconnaissance missions over Auschwitz-Birkenau. On August 25, they photographed the four cremas/gas chambers at Birkenau. In the images, the underground gas chamber rooms in Cremas/Gas Chambers 2 and 3 are visible from the outline of the berm of earth and grass that covered them. The chimneys are clearly visible on the roofs of both buildings, as four dark squares are staggered down the length of the roof.[7]

    Holocaust deniers claim that these aerial photos have been tampered with and the black marks on the roofs were added later.[8] In 1996, experts at NASA’s Jet Propulsion Laboratory in Pasadena, California, world leaders in the analysis of aerial and satellite images, examined the negatives carefully. The JPL experts found no evidence of forgery or tampering, proving that the markings on the roofs were on the original negative.[9]

    The Nazis also photographed the construction work on the cremas/gas chamber buildings. In December 1942, they took a picture of the construction work underway on Crema/Gas Chamber 2. The picture included the roof of the gas chamber room shortly before its completion and before it was covered with dirt. Behind the train’s engine, the four chimneys on the roof and the shadows they cast are clearly visible.[10]

    Why it is difficult to find the holes in the gas chamber roofs today?

    In late 1944, the cremas/gas chambers buildings in Birkenau were dismantled and blown up by the Nazis in an attempt to erase the physical evidence of the genocide. After their demolition, the underground undressing room and gas chamber room in Cremas/Gas Chambers 2 and 3 basically turned into sunken rectangles full of concrete and rubble. The part of the buildings that housed the ovens, which was aboveground, are heaps of crushed concrete, masonry, and metal.[11]

    Still, there is physical evidence for the gas chamber holes:

    A rigorously conducted forensic study was done in 2000 by qualified experts. These experts were able to identify the location of three of the four holes in the badly damaged roof of Crema/Gas Chamber 2. The study found “clear signs of openings; straight cast edges in the concrete of the roof; rebar cut cleanly (i.e., not stretched by the explosion); the absence of rebar in the area within the holes; and the presence of rebar bent inwards at the edges of the holes.”[12] The fourth hole is partly hidden by a fold in the rubble that was created by the explosion; only the edge of it can be seen.


    There were holes in the gas chamber roofs at Auschwitz-Birkenau. The Nazis poured Zyklon-B through these holes in order to murder their victims. The eyewitness testimony of perpetrators and survivors confirms these holes. And, photographic images taken in 1944 by both the Allies and the Germans show the hole chimneys of Cremas/Gas Chambers 2 and 3. Finally, a thorough forensic study conducted in 2000 has located and proved beyond doubt that these holes existed. The deniers’ claim of “No Holes, No Holocaust” does not stand up to scrutiny.


    [1] Transcript, Day 11, January 28, 2000, p. 151 at https://www.hdot.org.

    [2] Robert Faurisson, “The Gas Chambers of Auschwitz” (“Appeal to UNESCO”) at http://www.ihr.org/jhr/v18/v18n5p12_Faurisson.html.

    [3] The “Holes in the Roof” issue only relates to Cremas/Gas Chambers 2 and 3 in Birkenau. In Cremas/Gas Chambers 4 and 5 and in the two cottages at the back of Birkenau that were used as temporary gas chambers, the Zyklon-B was poured in through openings in the walls. There is no trace today of the walls of these four cremas/gas chambers.

    [4] Filip Müller, Eyewitness Auschwitz: Three Years in the Gas Chambers (Ivan R. Dee, 1999), pp. 60, 115.

    [5] Shlomo Venezia, Inside the Gas Chambers: Eight Months in the Sonderkommando of Auschwitz (Polity in association with the United States Holocaust Memorial Museum, 1999), pp. 68, 69.

    [6] Robert Jan van Pelt, Van Pelt Report (“IX The Leuchter Report”) at https://www.hdot.org.

    [7] You can see this image at http://www.jewishvirtuallibrary.org/jsource/Holocaust/aerial1.html. See August 25 image, captioned by CIA. In the enlargement you can clearly see the four chimneys on each of the roofs of Cremas/Gas Chambers 2 and 3.

    [8] John Clive Ball, “Air Photo Evidence” (“6. Conclusions”) at http://vho.org/GB/Books/dth/fndaerial.html.

    [9] Robert Jan van Pelt, Van Pelt Report (“VI Blueprints of Genocide”)

    [10] You can see this image at Jamie McCarthy, “Zyklon Introduction Columns” at http://phdn.org/archives/holocaust-history.org/auschwitz/intro-columns/

    [11] You can see what these buildings look like today at http://www.scrapbookpages.com/AuschwitzScrapbook/Tour/Birkenau/RuinsII01.html.

    [12] Daniel Keren, Harry W. Mazal and Jamie McCarthy, “The Ruins of the Gas Chambers: A Forensic Investigation of Crematoriums at Auschwitz I and Auschwitz-Birkenau,” Holocaust and Genocide Studies, 18(1), Spring 2004 at https://phdn.org/archives/holocaust-history.org/auschwitz/holes-report/holes-intro.shtml. See “Part I: Recent Findings.”