That '70s Show star Lisa Robin Kelly died yesterday of unknown causes in a rehab facility. The actress, who was only 43 years old, had a troubled past and had many encounters with police following her rise to fame on the show in which she played Laurie Forman, the older sister of Topher Grace's character.

Kelly was arrested this June on suspicion of drunken driving and was previously arrested along with her husband last November after a disturbance at their home in North Carolina.

Kelly's agent Craig Wyckoff released the following statement:

'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.'

'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. Cause of death has not been issued yet and no death certificate has been issued either.'

Co-stars have yet to respond to the sad news, with the exception of Danny Masterson who played Hyde on the show who tweeted: