Totalitarianism the Horror

Arendt explains that the best example of totalitarian rule is the concentration camps. That nothing else can ever be compared to the horror that occurred there because the Nazis made it so. Hitler outright said that he had to create a situation so unbelievably awful that people overlooked it as a lie to really get away with committing such atrocities. My friend works for a Jewish museum in Indiana where the director and founder of the museum is a concentration camp survivor. Recently she took my friend with her to the anniversary of the closing of the camp she was in in Poland. My friend, who has never had trouble talking about anything before, was speechless when I asked what it was like. She said that just being on the ground that such terrible things happened on was an indescribable experience. The isolation Arendt talks about in the book seems, to me at least, unfathomable. How can so many people be corralled in one place and not have any idea what is going on? Why did so many people overlook what was going on? How could so many people assist in these horrible things? My friend understood these when she came back from Poland. The only way she could describe it was the atmosphere; the pictures, the stories, the memories, they made her better understand what really happened.