Salomon Ostaszewer was born in Sierpc in Poland. He held an administrative position in his father’s oil factory until 1920, then moved to Berlin and worked as a managing director until 1938. After that he had to perform forced labor. When he was threatened with deportation in November 1942 he went into hiding. He initially stayed with a relative, Gertrud Dobrin, in her “Aryan” fiancé Richard Klindzan’s apartment on Alexanderstraße in Berlin-Mitte. Klindzan also took in Ostaszewer’s colleague Martin Grünberg. When he was to be drafted into the Wehrmacht in 1944, Klindzan deserted and went underground himself.
Martin Grünberg’s non-Jewish sister-in-law Marie Grünberg then took the three Jews and the deserter into her apartment in the Mitte district, while she and her Jewish husband Kurt lived on their garden plot in Blankenburg. When the air raids on Berlin grew ever more intensive, Marie Grünberg hid the other men in Blankenburg as well, despite the risk that posed for her husband in particular. She occasionally also took in her husband’s nephew. All of them survived.