Superman's Lois Lane, Margot Kidder, has died at the age of 69.
PEOPLE confirmed the Hollywood megastar died at her home in Livingston, Montana, on Sunday. Her cause of death is still unknown.
Rising to fame in 1978 for her role as Lois Lane in Superman: The Movie opposite Christopher Reeve, Kidder went on the reprise the part in the movie's three sequels.
Kidder also starred as Kathy Lutz in The Amityville Horror (1979), and appeared in movies such as Black Christmas (1974) and Heartaches (1981). The actress also starred as Eliza Doolittle in the 1983 adaption of Pygmalion.
Despite her raging success, Kidder battled mental health issues throughout her life, at one point leaving her homeless.
Kidder told PEOPLE five months later that the root of most of her problems, which included 'mood swings that could knock over a building', was manic depression.
'It’s very hard to convince a manic person that there is anything wrong with them,' said Kidder. 'You have no desire to sleep. You are full of ideas.'
Kidder is survived by her daughter, Maggie McGuane.
This article originally appeared on New Idea.
