For some weird reason all the camps investigate by the United States after WW2 ended up just being concentration camps and only the ones in the territory controlled by Russia were found to be death camps. Even more interesting is that there were multiple sources claiming there were 6 million total in all of Europe and somehow the Germans managed to capture and kill all 6 million but then many also were alive afterwards to collect reparations and to tell stories of rollercoasters leading to furnaces and machines that jacked people off to death. There were also wooden doors that opened into the chambers and were able to be opened from inside so it's pretty surprising you could pack people into a room so tightly they could only stand up, then pump in deadly gas, and they were nice enough to not pile up in front of the door in their effort to escape so that it would be possible to open the door after they were all dead.