World War II era documents that were not shown to the public until recently show that the Allies knew about Nazi death camps well before D-Day.

United Nations War Crimes files show that as early as 1942 and ’43, officials were aware of Nazi Death Camps, and were already writing up indictments on Adolf Hitler and other Nazis for their crimes including the extermination of the Jews.

British historian and researcher Dan Plesch says the early research shows that more could have been done to rescue Jews from the camps by using escape routes through the Balkans and France, even before 1944.

6 million Jews were murdered in death camps throughout Europe during World War II.