The actress played Liesl in the beloved musical.
Charmian Carr, who portrayed Liesl, the eldest von Trapp daughter, in The Sound of Music, has died at age 73.
The actress died in Los Angeles, California, after complications from a rare form of dementia, according to her website.
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Carr famously performed "Sixteen Going on Seventeen" in the 1965 movie, and later wrote two books, Forever Liesl and Letters to Liesl, about her experience on The Sound of Music set. Following news of Carr's death, Kym Karath, who played Gretl in the film, tweeted: "She has been like a sister throughout my life."
In addition to acting, Carr went on to run an interior design firm in California.
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Carr is survived by several sisters and brothers, two children, a niece and four grandchildren.
The real-life Liesl, Agathe von Trapp, the eldest daughter of the Austrian family who inspired the film, died at the age of 97 in 2010.
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