Felix Frank was a son of Alexander Frank and Sophia de Vries. He married in Rotterdam on 21 June 1934 to Fredij Ziekenoppasser, who survived the Holocaust. However Felix took his own life on 2 September 1943 due to pressure and the circumstances.
City Archive of Amsterdam, archive card of Fredij Ziekenoppasser and Wedding regisgter of the Municipal Archive of Rotterdam.
The funeral records at the Jewish cemetery in Rotterdam reveal that Felix Frank was buried there.