A few facts from the American Holocaust Museum:
There were 44,000 concentration camps operated by the Nazi political régime between 1933 and 1945
There were more than 18,000,000 deaths in those camps including:
@ 6,000,000 Jews
@ 5,700,000 Soviet Civilians
@ 3,000,000 Soviet POW's
@ 2,000,000 non-Jewish Polish citizens
@ 500,000 Serbs
@ 300,000 "Gypsies"
@ 270,000 disables German Citizens
@ 10,000 Male homosexuals
And only Bonhoeffer knew? He pleaded in vain for the church to speak out. History records the answer.