Complex sentence: Auschwitz II extermination program resulted in the death of 1.3 to 1.5 million people, over 1.1 million of them Jews from across Europe including 200,000 children.
Split into simpler sentences: Auschwitz II extermination program resulted in the death of 1.3 to 1.5 million people. Over 1.1 million of them were Jews from across Europe including 200,000 children.