Although there were already rumors of mass murders of Jews during the war, it was only after the end of the war that Manfred learned of the fate of his parents and sister.

His sister Marianne Paula was sent by her parents to the Netherlands on a “Kindertransport” [children transport] in January 1939 at the age of twelve, in the hope that she would be safe there. From July 1939 Marianne lived with the Wegloop family in Eindhoven. Together with her host family, she went into hiding for a short time in 1942, but was discovered by the Gestapo. In August 1942, she was deported to Auschwitz via Westerbork and murdered there on September 3, 1942.

Manfred's parents had been deported to the Jungfernhof camp near Riga in December 1941 and died there.