Complex sentence: Lillian's mother died on April 15,1964, the 52nd anniversary of the sinking, and her brother, Felix, with whom Lillian lived, died on March 15,1983.
Split into simpler sentences: Lillian's mother died on April 15,1964, the 52nd anniversary of the sinking. Her brother Felix, with whom Lillian lived, died on March 15,1983.