Most Germans knew what was going on,as farmers fertilized their fields with the ashes and used slave labour.Criminals and others were regularly released from KZ's for war duty or work details.Shaven headed slave labourers were everywhere,in public offices too.
A whole industrie lived off the extermination camps and its byproducts.Hair,bones belongings,all efficiently recycled.
My relatives documented these things,photographically and in diaries,as they harboured escapees plus french parachuters and newly released Dachau inmates.My relative was 3 times in Dachau as a a comunist leader of gypsy origin,active in the resistance.
Slave labour was the best survival chance,what they had to do to survive is not often talked about.Many ex KZ inmates,served in so called Straf Battalions in suicidal war campaigns,only a few survived.
The german resistance is mostly ignored by history,as it was based on comunist sympathizers and Raete Republic leftovers.
I attribute the denial of knowledge of what was happening to simple psychological shame.
Every german knew the phrase KZ and threats from Blockwards(form of informer janitor)were common, like you'll end up through the chimney.Kids used it in rhymes.
Some of the comments in this thread are a insult to intelligence.Disguising antisemitism with religion is pathetic(JC slayers?).
We have not learned anything as witnessed in the former Yugoslavia with KZ situations,visited by the UN and Red Cross at the time.Or Pol Pot.The massacres in Africa.We still stand by and do nothing.Clintons admitted shame.UN united in doing nothing.
It is said that Churchill said why bomb the traintracks it will help us deal with the jewish situation.The surrounding war effort factories in KZ vicinities were well known as a target but left to continue.There have been docus about it.
All the allies were antisemitic at the time....it continues...
Today its the xenophobia hydra which rises its ugly head way to often...