@nprofile1q... Traces: https://codoh.com/library/document/an-official-polish-report-on-the-auschwitz-gas/
Missing holes in ceilling: https://www.researchgate.net/publication/31161925_The_Ruins_of_the_Gas_Chambers_A_Forensic_Investigation_of_Crematoriums_at_Auschwitz_I_and_Auschwitz-Birkenau

I have been at Auschwitz and a few camps when i was young and i can tell you people were definetly gassed there lol, Why even deny such a thing it was peak efficiency of the Nazi war machine, if anything it was impressive how effective they were at exterminating.

Not me siding with them but you have to give credit where its due, that was a well engineered execution method lol