Gas Chamber in the Auschwitz I Main Camp

According to Pressac, no material or documentary evidence of the gas chamber in the crematorium in the main camp exists, but there 

1 Vestibule 2 Laying-out room 3 Wash room 4 Morgue 5 Oven room 6 Coke 7 Urns  

As far as I know, no documents exist concerning the installation of a ventilation system into this morgue, though it appears inconceivable to operate a morgue without windows, exterior doors, and any kind of forced ventilation. 

The morgue was later alleged to have been converted into a gas chamber . Three to four hatches are later said to have been pierced through the roof for the introduction of the Zyklon B for homicidal 

1 Sluice 2 Operating room 3 Former washroom, now air raid shelter with 

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