Sanders was last seen leaving her waitress job at Pete's Patio Resturant in Niles, Michigan on July 20, 1975. Her estranged boyfriend, Gerald "Jerry" Libertowski, followed her out of the restaurant. Witnesses stated Libertowski was acting like a "mad man" at the time. Sanders had ended their relationship the week before and moved back in with her parents. She has never been heard from again. Sanders was reported missing by a family member on July 21. On August 5, her vehicle was found parked at the Holiday Inn in the 900 block of south Eleventh Street. There was no sign of her at the scene.

In 1976, Libertowski was charged with Sanders's murder as well as the murder of Janeice Langs, another girlfriend of his who disappeared in 1973 and was never found. Sanders's wallet and a pill bottle belonging to Langs were discovered hidden in the foundation of Libertowski's house after the women's disappearances. He was later acquitted of Langs's murder, and there was not enough evidence to prosecute him in Sanders's presumed death. Authorities continue to believe Libertowski was involved in both women's disappearances.

Foul play is suspected in Sanders's disappearance due to the circumstances involved. Some agencies give her date of disappearance as August 5, the day her car was found.