The Hess family, like millions of Jews, was taken from their home in Amsterdam by the Nazis in 1943. After spending time at Westerbork, a transport camp in Holland, the family of four was sent by train in 1944 to Bergen-Belsen, a concentration camp where more than 50,000 people were killed — including Anne Frank — twins Steven and Marion Hess, just 6 at the time, credit their parents for keeping them together. "The Holocaust seems like ancient history, so we have to find a way for it not to be that, for it to be a lasting lesson," Marion...