A number of celebrities have paid tribute to 'Happy Days' actress Erin Moran, following her sudden death over the weekend.

The 56-year-old actress - who was best known for playing Joanie Cunningham in the 1970s sit-com and spin-off show 'Joanie Loves Chachie' - was found dead at her home in Indiana on Saturday (22.04.17) and her 'Happy Days' co-stars and others in Hollywood took to social media to remember her.

Ron Howard - who played her on-screen brother Richie - and Henry Winkler, best known as The Fonz, were among the first to pay tribute to the late star on Twitter.

Director Ron wrote: ''Such sad sad news. RIP Erin. I'll always choose to remember you on our show making scenes better, getting laughs and lighting up tv screens (sic)''

And Henry tweeted: ''OH Erin... now you will finally have the peace you wanted so badly here on earth ...Rest In It serenely now.. too soon (sic)''

Don Most, who starred alongside Erin as Ralph Malph on the sitcom tweeted, ''So incredibly sad to hear about Erin. A wonderful, sweet, caring, talented woman. I can't really comprehend this right now. Very painful loss.''

He added in a statement: ''I am so incredibly sad to hear about Erin. She was a wonderful, sweet, caring, talented woman. As I write this I can't really comprehend this right now. A very painful loss. It gives me some comfort to know that she's with [co-stars] Tom [Bosley], Al [Molinaro], Pat [Morita] and [show creator] Garry [Marshall]. Rest In Peace, sweet Erin.''

Anson Williams, who played Potsie, said: ''Erin was a person who made everyone around her feel better. She truly cared about others first, a true angel. I will miss her so much, but know that she is in God's hands. RIP sweet angel.''

Willie Ames, who appeared in the TV show 'Gunsmoke with Erin, wrote: ''I've known Erin Moran since childhood doing 'GunSmoke.' More recently as a troubled soul. So saddened to hear of her passing. RIP ERIN xo (sic).''

Musician Dave Navarro shared a picture of her and wrote: ''#RIP #ERINMORAN,'' while actress Erin Murphy tweeted: ''So sad to share that my friend Erin Moran has passed away. Rest In Peace, sweet girl (sic).''

Harrison County Sheriff's Department in Indiana, confirmed Erin's death in a statement, saying: ''On April 22, 2017 at approximately 4:07 p.m., the Harrison County Dispatch received a 911 call that referenced an unresponsive female. Upon the arrival of first responders, it was determined that Erin Marie Moran Fleischmann was deceased and an autopsy is pending.''