All of this has been debunked many times over. When the Nazi’s knew they were losing they tried to dismantle what they could and what’s there now includes reconstructions for what is basically a museum. Wooden doors were sometimes used with carbon monoxide instead of cyanide which didn’t pose a threat to those outside. And the one ‘internet famous’ wooden door was apparently installed when the chamber was converted to an air raid shelter. Stop hating so much.