Pyle Peters was last seen at at Forest Hills Central Middle School in the 5800 block of Ada Drive southeast in Grand Rapids, Michigan on February 5, 1981. She was at her younger brother's wrestling practice with her mother when she said she was going to the women's restroom and would be back shortly. Pyle Peters never returned and has not been heard from since.

Pyle Peters apparently never arrived at the restroom; no one saw her anywhere near there. She was last seen walking out the door of the gymnasium; accounts differ as to whether she was going to a friend's home or merely wanted to smoke a cigarette. She left her wallet, purse, makeup, jewelry, clothing and several hundred dollars behind at home.

Two possible suspects in Pyle Peters's disappearance have since left the Grand Rapids area. Authorities checked the school incinerator on the theory that someone might have tried to burn her body, but found no evidence. Pyle Peters was not having any serious problems with her family when she disappeared, she was a good student, and she does not have a prior history of running away from home. Several possible suspects were questioned after her disappearance, but no on has ever been charged. She was an eighth-grader in 1981, and aspired towards a career as a model. She is originally from California, and her biological father was living there in 1981. Her mother and stepfather, with whom she lived, moved to Arizona after her disappearance.

Pyle Peters was declared legally dead in 1991. In 2008, authorities reopened the investigation into her disappearance and appealed for anyone who was at the school that day to contact them. Her Her case remains unsolved.