Lisa Robin Kelly, the actress who played Eric's older sister Laurie Forman on That '70s Show, passed away in her sleep at a rehab facility in California.
The 43-year-old actress, who had battled with alcoholism for some time, had voluntarily checked herself into the facility after supposedly falling off the wagon following a dispute with her ex-husband.
We're told Lisa's new boyfriend brought her to rehab again on Monday ... but she went into cardiac arrest late Wednesday night and could not be saved.
Kelly had been in a downward spiral for the past couple of years -- she was arrested at least 4 times in the past 3 years for DUI, spousal abuse and assault.
Lisa had filed for divorce from her husband Robert Gilliam back in July -- seeking to end a marriage that was littered with allegations of spousal abuse, by both parties.
Kelly had been arrested late last year after police responded to a disturbance at the home she had shared with her then husband.
Kelly had a number of smaller roles in other television programs and TV movies, but, according to IMDB, had only appeared in two shorts since the end of That '70s Show's run in 2003.
The official cause of death has not been disclosed. [TMZ]