Fritz was born on August 15, 1936, in Naumberg an der Saale, Saxony-Anhalt, Germany, to Fritz and Clara (den Hartog) Rathjens. Fritz spent the first ten years of his life in Nazi Germany and occupied Poland. After the war the family returned to the U.S. and shortly thereafter settled in the DC area. He graduated from Gonzaga College HS and attended University of Maryland. He was the small business owner of F M Rathjens Irrigation, a lawn irrigation company, for 40 years.
He was preceded in death by his parents and his son, John David. His sister Claartje Bertaut passed away later on December 4, 2022. He is survived by his daughter Jennifer, son Fritz Jr., grandson Alexander (Danielle) Rathjens, great grandchildren Jessica and Eric Maarten, his sister Elizabeth Mendelsohn and several nieces and nephews.
There will be a graveside service at Union Cemetery, 3001 Spencerville Rd, Burtonsville, MD, at 3 pm on December 10, 2022.