Credit: Bobby Bank/WireImage

Patty Duke, the film, television, and stage actress who won an Academy Award at age 16 for her role as Helen Keller in A Miracle Worker, has died. She was 69.

Actor Sean Astin confirmed the death of his mother on Facebook. “This morning, our beloved wife, mother, grandmother, matriarch and the exquisite artist, humanitarian, and champion for mental health, Anna PATTY DUKE Pearce, closed her eyes, quieted her pain and ascended to a beautiful place,” read a statement on Astin’s official page. “We celebrate the infinite love and compassion she shared through her work and throughout her life.”

Duke’s husband, Michael Pearce, told the New York Times that his wife’s cause of death was sepsis caused by a ruptured intestine.

Duke, whose real name was Anne Pearce, was the youngest actress at the time to earn an Oscar (she first played Keller opposite Anne Bancroft on Broadway). Her rising star resulted in an eponymous sitcom that was created by Sidney Shelton and launched in 1963. The Patty Duke Show lasted until 1966.

Duke worked constantly in films like Valley of the Dolls and TV shows like Night Gallery, Police Story, and Hawaii 5-0 while privately battling biopolar disorder, which was revealed in her 1987 autobiography Call Me Anna: The Autobiography of Patty Duke. She went on to advocate for the mentally ill by working with the National Institute of Mental Health and the National Alliance on Mental Illness.

Duke won three Emmys, one of which was for playing the role of Anne Sullivan in the 1979 adaptation of The Miracle Worker for NBC.

Among those who paid tribute to Duke on social media were Marlee Matlin, Rose McGowan, Kristy Swanson, William Shatner, and Melissa Gilbert.

“Brave, outspoken and humanitarian who played Helen Keller in Miracle Worker Oscar winner Patty Duke passed. I will miss her,” wrote Matlin.

Duke is survived by her fourth husband, Michael Pearce, and her children Sean Astin, Mackenzie Astin, and Kevin Pearce.