Holocaust Memorial Day

Robert, one of my great grandfathers, was lucky.  He emigrated to London in the 1890's and had a successful life and many descendants.  It was his two sisters who perished in the camps, and possibly their families - we do not know about them.  The two women would have been in their 70's so perhaps the horrors were short-lived as what use would they have been to anyone.  I would like to remember them today.