Open this photo in gallery: Alex Buckman, who survived the Holocaust as a young boy after a heroic rescue by a Belgian teacher, visits Poland as part of an event called March of the Living in April when this photo was taken. He died there just days after the photo was taken.Fedele Arcuri/March of the Living Alex Buckman was not quite 4 when he was with his parents for the last time – although he didn’t actually see his mother that day. She remained concealed behind a closed door. The family lived in Belgium, which had been invaded by the...