Jayme Deerwester

USA TODAY

Erin Moran, who was best known for playing Joanie Cunningham on the long-running comedy Happy Days and its short-lived spinoff, Joanie Loves Chachi, has died at 56.

Her death was announced by police in Harrison County, Ind., after they responded to a 911 call and found her unresponsive Saturday afternoon, the Associated Press has confirmed. Her death was first reported by TMZ.

No cause of death has been determined.

Moran, who was born Oct. 18, 1960, in Burbank, Calif., landed her first big role on the children's adventure show Daktari when she was just 8. The show premiered the same year she made her film debut opposite Debbie Reynolds in How Sweet It Is.

She occupied herself with TV work until she landed the role of the youngest child of the Cunningham family. The series, which took place between 1955 and 1965, premiered on ABC in 1974. She left to star in its spinoff, Joanie Loves Chachi, but that show was canceled after one season. She rejoined the Happy Days cast for its final season, which ended in 1984.

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Her post-Happy Days credits include guest stints on The Love Boat and Murder, She Wrote.

Moran also jumped on the reality TV bandwagon, doing a season of VH1's weight-loss show Celebrity Fit Club in 2008.

Her most recent acting credit was 2010's Not Another B Movie.

She was back in the headlines a year later, when she joined several other members of the Happy Days supporting cast in suing CBS, the studio that produced Happy Days, for withholding royalty money they were entitled to under their contracts. In 2012, each of them won a $65,000 settlement and the rights to future royalties.

It was a welcome infusion of cash for Moran, who had only a handful of acting gigs in the last 25 years according to IMDb.com, and was said to be living in an Indiana trailer park and struggling with personal issues.

Ron Howard, who played Richie, her big brother on Happy Days, tweeted, "I will always choose to remember you on our show making scenes better, getting laughs and lighting up TV screens."

"Now you will finally have the peace you wanted so badly here on Earth," added co-star Henry Winkler, who played the Fonz.

Scott Baio, who was Moran's beau both on and offscreen, paid fond tribute his ex-girlfriend.

"May people remember Erin for her contagious smile, warm heart, and animal loving soul. I always hoped she could find peace in her life," he wrote Sunday. "God has you now, Erin."

Contributing: The Associated Press