Patty Duke, who won an Oscar as a teenager for The Miracle Worker and maintained a long and successful career throughout her life, has died at the age of 69.

Duke's agent, Mitchell Stubbs, said the actress died early on Tuesday morning of sepsis from a ruptured intestine. She died in Coeur D'Alene, Idaho, according to Teri Weigel, the publicist for her son, actor Sean Astin.

Glasgow Times:

Duke, born Anna Marie Pearce, followed on her early success playing the young Helen Keller with a popular sitcom, The Patty Duke Show, which aired in the mid-1960s. She played dual roles under a then-unconventional premise: identical twins living in Brooklyn Heights.

Duke was also an outspoken advocate for mental health. She was diagnosed as bipolar in 1982 after years of battling mental illness.