An insert in the marriage certificate says that the groom (Ehemann) died on 29/01/1940 and cites a Breslau death certificate.

His parents, Louis Waldhorn and Berta geb. Jaroczewer, are named in his death certificate.

Isidor is listed in the Breslau synagogue community address list (ca 1930) with his parents and presumed siblings at Graebschenerstrasse 51; his 1932 marriage certificate gives the same address.