LOS ANGELES - CIRCA 1962: Actress Patty Duke attends a party in Los Angeles, California.
Michael Ochs Archives/Getty Images

Patty Duke, a legend of stage and screen, has passed away, her agent confirmed to the Associated Press. She was 69 years old; the cause of death has yet to be determined.

Duke won an Oscar at the age of 16 for her role as Helen Keller in The Miracle Worker in 1962; following that young achievement, the Queens native starred in Valley of the Dolls, Billie and Me, Natalie in the 1960s. Meanwhile, Duke starred in The Patty Duke Show, an ABC sitcom that ran for three years after debuting in 1963.

Duke continued to work on television from the 1970s to the 2000s, earning Emmys for a new version of The Miracle Worker, Captains and the Kings and My Sweet Charlie. In addition, Duke enjoyed a successful Broadway career and singing stint, notching Top 40 hits with “Don’t Just Stand There” and “Say Something Funny” in 1965.

Duke was diagnosed with bipolar disorder in 1982 and had been an outspoken mental health advocate. She married Michael Pearce in 1986, and was the mother of actor Sean Astin.