An autopsy of "Happy Days" star Erin Moran showed that she probably died of cancer, according to the Harrison County Sheriff's Office and the county coroner.
A statement released by authorities Monday said that an autopsy found that Moran "likely succumbed to complications of stage 4 cancer."

The Sheriff also said "standard toxicology tests were performed and the results are pending, however no illegal narcotics were found at the residence."
The actress played Joanie Cunningham for most of the sitcom's decade-long run in the 1970s and 1980