With the full knowledge of the Catholic Church.
What’s that supposed to mean?
FYI, Dachau was also the designated prison camp for thousands of professed Christians: Germans, Polish, French, and Belgian. Most of them were Catholic priests and bishops. The nazis hated the Catholic Church.
Poland lost more citizens to the Nazis than any other group, including the slaughter of entire monastic communities. That might explain the fear and silence of those who survived.
We, here in the USA where we have never known the fear of night raids, concentration camps, and religious persecution ought to be a bit more cautious in our condemnations of those who actually lived through it.