The death of Erin Moran has hit her Happy Days family hard. Following the news that the actress, who played Joanie Cunningham in the family sitcom and its spin-off Joanie Loves Chachi, died at the age of 56 on Saturday from as-yet-undetermined causes, several of her co-stars have spoken out to commemorate the actress.

Ron Howard, who portrayed her brother Richie Cunningham on the hit series, wrote on Twitter, "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."

Henry Winkler
, who played Arthur "The Fonz" Fonzarelli also wrote, immediately after the news, "OH Erin... now you will finally have the peace you wanted so badly here on earth ...Rest In It serenely now.. too soon."

In a statement to Variety, Winkler added, "I will always remember Erin with her sweet smile that greeted me on the very first day I walked onto the set of Happy Days in 1974. She was only nine years old. For the next 10 years that smile never faded. Unfortunately yesterday it did. My condolences go out to her family. She will always be locked in my heart."

Scott Baio, who played Chachi to Moran's Joanie, remembered the actress' "contagious smile" and "warm heart" on Twitter Sunday.

Meanwhile, co-star Don Most, who portrayed Ralph in the show, released a statement to The Hollywood Reporter, saying, "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 Tom, Al, Pat and Garry. Rest In Peace, sweet Erin."

Anson Williams, who portrayed Potsie on Happy Days, also remembered his co-star in a statement to THR, writing, "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."

Others from Hollywood have also paid tribute to Moran.

Moran, who also appeared on The Love Boat and Murder, She Wrote, publicly struggled with alcoholism and financial stresses following her meteoric rise to fame as a child star.

Although her Happy Days and Joanie Loves Chachi work would inform her career for a full decade, she had trouble maintaining that mainstream status after they ended. She did enjoy small roles in films like Dickie Roberts: Former Child Star and Not Another B Movie, but was largely absent from the Hollywood scene in the 2010s.

The Harrison County Sheriff's Department in Indiana confirmed that officers were called to her home on Saturday in response to reports of an unresponsive woman onsite and found her deceased from unknown causes. An autopsy is pending to determine the cause of Moran's death.