Weisser would remain with his mother in Antwerp until September 11, 1942, where she was arrested in public and later deported to and murdered in Auschwitz-Birkenau as part of the Holocaust.

With the arrest of his mother, and lacking both his parents, he was rescued by an unknown individual and brought to the children's home of Meisjeshuis.

The exact circumstances surrounding both the arrest of his mother and his retrieval remain unclear, but his appropriation of orphan status would ensure protection against deportation.

[further explanation needed] On September 21, 1942, twenty five Jewish children who were with Weisser in Meisjeshuis were arrested after surpassing toddlerhood through reaching the age of 5 and all deported to Auschwitz-Birkenau, where they died.

[4][a] His father would survive several concentration camps (notably Auschwitz-Birkenau as well as Buchenwald in its final days) and a death march during the German retreat from Poland, reuniting with Weisser in 1945.