Sander's parents had come to Amsterdam from Wroclaw. He was half-Jewish and lived in Eerde from 1941. After the closure of the school in 1943 Ulrich went back to Amsterdam. In October 1944 he was arrested during a raid and deported to Germany.
After Ulrich Sander was able to flee twice and was beaten to almost death as a result, he died of the consequences of the abuse in the hospital of Enschede.