Margot Kidder passed away on Sunday at her home in Livingston, Montana, People reports, She was 69. Her cause of death is unknown.
Funeral arrangements for the Canadian-born actress are pending.
Kidder began acting in the late 1960s, but rose to fame in 1978 for her role as Lois Lane in Superman: The Movie opposite Christopher Reeve. She went on to reprise the part in the movie’s three sequels.
She also starred as Kathy Lutz in The Amityville Horror (1979), and appeared in movies such as Black Christmas (1974) and Heartaches (1981). Kidder acted as producer and starred as Eliza Doolittle in a 1983 adaptation of Pygmalion with Peter O’Toole for Showtime.