Troubled actress Lisa Robin Kelly died from multiple drug intoxication, the Los Angeles County coroner's office said in its final autopsy report. EW.com said the report was released last Friday, but did not say what drugs were found in Kelly's system. Best known for playing Eric Forman's sister, Laurie, on the sitcom "That '70s Show," Kelly died last August at the age of 43. The actress had a history of addiction to illegal substances, EW.com said. She was arrested at least four times during the past three years for driving under the influence, spousal abuse and assault.