In 1937, he left Bydgoszcz with his wife and settled in Hamburg. Initially, they lived with their older son Hans, but moved in 1939 to their own flat. During World War II, Fritz and Alice moved to their daughter's house, Margarete Bublitz, in Wysoka, near Schneidemühl (Piła). Thanks to this, they avoided the tragic fate of many inhabitants during the allied air raids on July 24–30, 1943, when their Hamburg apartment was flattened.