The actress, best know for her role as Lois Lane in the Superman movies died on Sunday.
According to TMZ,
“…an unknown person called police to report Margot was unconscious and not breathing. Police responded and found her dead. The Livingston Police Chief says foul play is not considered a factor, but her death is now under investigation. ”
Kidder was apparently at her home in Montana when she passed and is survived by her daughter.