My maternal grandfather was Bernard Hart (ne Herzkowicz, various spellings). He died before I was born. My cousin Jennifer Henley is also a member of the Zychlin group. She has posted an interesting article on the site on how we found out about the circumstances of his death. Bernard and his brother, Mark Hart, came to the UK leaving several siblings behind in Zychlin. We do not know what happened to the siblings and their families.
Mavis Henley