The cause of death behind That 70s Show actress Lisa Robin Kelly remains a mystery.

Kelly,43, checked herself into Pax Rehab Center in Altadena, California Monday and was found dead in her bed Thursday.

Kelly long struggled with drug and alcohol abuse and prior to her death the actress was reportedly trying to clean up her act. TMZ reports that reps for the rehab facility stand firm that they did not give the troubled actress any drugs prior to her death.

Also, Kelly did not show any signs of trauma. There was no vomit found in her air way, and no drugs or alcohol were found her room at the time of her death. The LA coroner notes that her death remains a “mystery.”
According to TMZ, at the time she entered the rehab facility on Sunday with her boyfriend, she blew a .34 blood alcohol level.

Kelly is currently undergoing an autopsy. New details should follow after the results are released.

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