Williams was last seen on December 7, 1978. She left her residence in the 500 block of east Gibson Street in Scranton, Pennsylvania that day, driving her red 1977 Datsun 200 SX with white racing stripes, to go to an exercise class at her dance school. Williams left the dance school, which was located on Route 6 in Chinchilla, Pennsylvania, at 10:00 p.m. She never arrived home and has never been heard from again.

On December 16, 1978, nine days after Williams vanished, her car was found parked at Lafayette Street and north Everett Avenue. It was unlocked and inside was her paycheck and her purse with its contents undisturbed. There was no sign of Williams at the scene.

Frank Osellanie is considered a possible suspect in Williams's case. He was convicted of kidnapping, raping and murdering a nine-year-old Scranton girl in 1990 and has been in prison ever since. He is considered a person of interest in several other cases, including the 1986 disappearance of Michelle Lakey. Osellanie says he did not know Williams. He maintains his innocence in all the cases and investigators are not sure whether he was involved.

Williams's case remains unsolved. She was declared legally dead in 1991.