CORYDON, Ind. (AP) — Authorities say former "Happy Days" star Erin Moran likely died from cancer at her southern Indiana home.

A statement released Monday by the Harrison County Sheriff's Department says an autopsy revealed the 56-year-old actress had stage-four cancer, but doesn't specify what type.

The department says Moran died Saturday in the rural community of New Salisbury, about 20 miles northwest of Louisville, Kentucky. Officials say standard toxicology test results are pending but that no illegal narcotics were found at the home.

A Burbank, California, native, Moran began acting in TV and movies before she was 10 years old. In 1974, she was cast in "Happy Days" as Joanie Cunningham, the kid sister to high school student Richie Cunningham, played by Ron Howard.