Editing Gas chamber (section)

==Nazi Germany==
{{See also|Extermination camp#Gassings|The Holocaust#Extermination camps|Evidence and documentation for the Holocaust#Use of gas chambers}}
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[[File:Majdanek Komora Gazowa.JPG|thumb|Interior of Majdanek gas chamber, showing [[Prussian blue]] residue]]

[[Nazi Germany]] made extensive use of various types of gas chambers for mass-murder during [[the Holocaust]].

Beginning in 1939, gas chambers were used as part of ''[[Aktion T4]]'', an "[[involuntary euthanasia]]" program under which the Nazis murdered people with physical and intellectual disabilities, whom the Nazis considered [[Life unworthy of life|"unworthy of life"]]. Experiments in the gassing of patients were conducted in October 1939 in occupied [[Poznań]] in Poland. Hundreds of prisoners were murdered by [[carbon monoxide poisoning]] in an improvised gas chamber.<ref name="browning">{{cite book |title=The Origins of the Final Solution: The Evolution of Nazi Jewish Policy, September 1939 – March 1942 |publisher=Arrow |last=Browning |first=Christopher |year=2005 |isbn=978-0-8032-5979-9}}</ref> In 1940, gas chambers using bottled pure carbon monoxide were established at six killing centres in Germany.<ref name="USHMM-HE">{{cite web |url=https://www.ushmm.org/wlc/en/article.php?ModuleId=10005220 |title=Gassing Operations |website=Holocaust Encyclopedia |publisher=United States Holocaust Memorial Museum |access-date=30 November 2017 |url-status=live |archive-url=https://web.archive.org/web/20171203210358/https://www.ushmm.org/wlc/en/article.php?ModuleId=10005220 |archive-date=3 December 2017}}</ref> In addition to persons with disabilities, these centres were also used during [[Action 14f13]] to murder prisoners transferred from concentration camps in Germany, Austria, and Poland. Concentration camp inmates continued to be murdered even after the euthanasia program was officially shut down in 1941.<ref name="klee">{{cite book |title=Euthanasie im NS-Staat. Die Vernichtung lebensunwerten Lebens |trans-title=Euthanasia in the NS State: The Destruction of Life Unworthy of Life |language=de |last=Klee |first=Ernst |year=1983 |publisher=Fischer Taschenbuch Verlag |location=Frankfurt am Main |isbn=978-3-596-24326-6}}</ref>

During the [[Operation Barbarossa|invasion of the Soviet Union]], mass executions by [[exhaust gas]] were performed by ''[[Einsatzgruppen]]'' using [[Nazi gas van|gas van]]s, trucks modified to divert engine exhaust into a sealed interior gas chamber.<ref name="USHMM-HE" />

Starting in 1941, gas chambers were used at [[extermination camp]]s in Poland for the mass-murder of [[Jews]], [[Romani people|Roma]], and other victims of [[the Holocaust]]. Gas vans were used at the [[Chełmno extermination camp]]. The [[Operation Reinhard]] extermination camps at [[Bełżec extermination camp|Bełżec]], [[Sobibór extermination camp|Sobibór]], and [[Treblinka extermination camp|Treblinka]] used exhaust fumes from stationary [[diesel engine]]s.<ref name="USHMM-HE" /> In search of more efficient killing methods, the Nazis experimented with using the [[hydrogen cyanide]]-based [[fumigation|fumigant]] [[Zyklon B]] at the [[Auschwitz concentration camp]]. This method was adopted for mass-murder at the Auschwitz and [[Majdanek concentration camp|Majdanek]] camps. Up to 6,000 victims were gassed with Zyklon B each day at Auschwitz.<ref name="USHMM-HE" />

Most extermination camp gas chambers were dismantled or destroyed in the last months of [[World War II]] as [[Soviet Union|Soviet]] troops approached, except for those at [[Dachau concentration camp|Dachau]], [[Sachsenhausen concentration camp|Sachsenhausen]] and Majdanek. One destroyed gas chamber at Auschwitz was reconstructed after the war to stand as a memorial.