In 1933, the Nazi party authorized a small chain of internment camps in Germany, for the confinement of homosexuals, jazz musicians, atheists, prostitutes, and others who were deemed a threat to public morality. German corporations were invited to set up small factorys in these camps, and to exploit the prisoners as slave labour.
Profits were good.
Fast forward to the war, and millions of displaced people are vulnerable to exploitation. Several German corporations, and a few multi-nationals, are given the go-ahead to build more camps in occupied Poland to exploit these displaced people.
From mid 1941 to early 1945, millions of christians, jews, muslims, roma, atheists, budhists, and other people deemed unfit for inclusion in the new Greater Germany, were herded into these slave labour camps. At first only slavic people (Russians and Poles) are shipped to the camps. But over time western europeans are also sent.
They were ruthelessly exploited, and often worked to death, under conditions of extreme brutality.
Feeding slaves cuts into profit margins, so slaves are not fed.
Starvation and disease become major killers.
Finaly, in late '44/early '45, as defeat becomes inevitable, slaves are simply slaughtered to keep them from testifying at future war-crimes trials.
The multi-national corporations who had factorys in the camps, made a killing.
Germany was left holding the bag.