Erin Moran, who was best known for playing the role of Joanie Cunningham in "Happy Days" and "Joanie Loves Chachi", has passed away at the age of 56.

Authorities in Harrison County, Indiana say that she was found unresponsive Saturday afternoon after receiving a 911 call. The cause of death is still undetermined.

Moran has had numerous struggles over the last several years. In 1988, she revealed in an interview that she battled depression and was unable to gain acting roles. Earlier this year, Variety magazine said she was reportedly kicked out of her trailer park home in Indiana because of her hard-partying ways.

Moran was already a veteran actress when in 1974 she was cast as Richie Cunningham's (Ron Howard) little sister in "Happy Days". She would later appear with Scott Baio in the "Happy Days" spin-off series "Joanie Loves Chachi".

Erin Moran leaves behind her husband of nearly 24 years Steven Fleishcmann.