'Night Will Fall' is catching some current buzz due to being available on HBO streaming. It's based on footage from military cameramen that entered the Nazi concentration camps with the liberating troops, edited into a documentary in 1945-46. That project ended unfinished as it became time to stop being mad at the Germans and start being mad at the Russians.
The HBO feature intersperses documentary footage with interviews of survivors (on all sides) and others telling about both the documentary's subject, and what happened to the film.
For the straight dose, you can go to Frontline and see their 1985 production of the original 1946 documentary, "Memory of the Camps." It's as much as they could recover, without any new material. Trevor Howard reads the original script. Unless you've already viewed this Frontline piece, this is more and rougher than what you've ever seen before of this stuff.
http://www.pbs.org/wgbh/frontline/fi...-of-the-camps/
The takeaway: if they can do it, anyone can do it. This is part of what the human race is.