HELENA, Mont. (AP) - Margot Kidder's daughter says the Superman actress' death has been ruled a suicide. Maggie McGuane told The Associated Press Wednesday that she knew her mother died by suicide when she was brought to Kidder's Montana home in May, and that it is a big relief to have the truth out. Park County Coroner Richard Wood said in a statement that Kidder died May 13 in her Livingston home "as a result of a self-inflicted drug and alcohol overdose." McGuane says she believes it's important to be open and honest about the suicide so there's no cloud of shame. She says it's a unique sort of grief and pain and that she would like to reach out to every family who is suffering through a loss by suicide.