Lisa Robin Kelly, the actress who starred in That '70s Show, died on Wednesday 14th August.Her representative, Craig Wyckoff, issued a statement announcing her death. So far the 43-year-old's cause of death is unknown.

Lisa Robin Kelly
Lisa Robin Kelly photographed for That '70s Show in 1999.

It seems Kelly was in a rehab facility in order to deal with her addiction problems. Wyckoff last spoke to his client on Monday when she seemed to be doing well. On this conversation he said "I spoke to her on Monday and she was hopeful and confident, looking forward to putting this part of her life behind her."

In the statement, reported by CNN, Wyckoff said "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." 

Her cause of death is not certain and a death certificate has not been issued. It is unknown when these details will come to light. Kelly's representative merely said of his client's death: "last night she lost the battle. Cause of death has not been issued yet and no death certificate has been issued either." 

According to TMZ, who broke the news, Kelly went into cardiac arrest on Wednesday evening at the rehab facility in L.A. Her boyfriend had driven her to the rehab facility after taking her to hospital on Sunday as her blood alcohol level was at .34. 

Lisa Robin Kelly
Lisa Robin Kelly photographed for That '70s Show in 1999.

Medical personnel, who treated the 43-year-old actress, told TMZ Kelly had needle marks on her arms. However, her boyfriend has denied any implications of drug use by saying the marks were from the hospital visit.  

Kelly was best known for starring in That 70's Show which ran on Fox between 1998 and 2006. Kelly played the role of Laurie, the elder sister of Eric Forman (Topher Grace). Kelly, on That 70's Show, worked alongside such actors as Mila Kunis, Ashton Kutcher, Wilmer Valderrama and Laura Prepon

Danny Masterson, who played the role of Steve Hyde on the show, expressed his sorrow on Twitter. He said the news was "terrible" and "awful". He paid tribute to the actress saying she was "brilliant" on That '70s Show. He bade goodbye to his former co-star writing "see u next time".

Kelly admitted she had a drinking problem in a number of interviews, according to reports by TMZ. Furthermore, as reported by the entertainment website, she had been arrested on four separate occasions since 2010 on DUI, spousal abuse and assault charges. 

Ultimately, as her representative said, "she had been fighting demons for a while and finally lost her battle."

Contactmusic sends their condolences to Lisa Robin Kelly's family, friends and colleagues. 

Lisa Robin Kelly and Ashton Kutcher
Lisa Robin Kelly and Ashton Kutcher on That '70s Show in 1999.