27-year-old actor Harry Hains' cause of death revealed

The Los Angeles Medical Examiner revealed Monday that Harry Hains, a 27-year-old actor known for his appearances in "American Horror Story" and the Netflix series "The OA," died from accidental "fentanyl intoxication."

His mother previously posted her son suffered from mental illness and addiction.

"He was 27 and had the world at his feet," she wrote on Instagram. "A brilliant spark shone bright too short a time."

She later posted Hains was "A lover of life ... a crazy, creative . Magical creature ... just on loan to spread magic."

"Heard you were flying around creating planets and new life forms," she added.

The medical examiner's report indicated Hains died on Jan. 7 in Los Angeles.