Lisa Robin Kelly, who played Eric Forman's sister Laurie on "That '70s Show", died in her sleep at a rehab facility Wednesday, her agent Craig Wycoff told The Wrap.

"Unfortunately Lisa Robin Kelly passed away last evening. Lisa had voluntarily checked herself into a treatment facility early this week where she was battling the addiction problems that have plagued her these past few years," Wycoff said. "I spoke to her on Monday and she was hopeful and confident, looking forward to putting this part of her life behind her. Last night, she lost the battle."

The 43-year-old actress had been battling alcohol addiction for the past few years and had been arrested several times for charges including DUI, spousal abuse and assault, most recently in June for suspicion of DUI in Burbank, CA.

"That '70s Show costar Danny Masterson tweeted, "Terrible,awful news. Brilliant on 70s.... See u next time LRK,kisses. RT @sdavis53: #RIPLisaRobinKelly aka Laurie Foreman."