The Sound Of Music star Charmian Carr has died at the age of 73.
The actress's spokesman said she died on Saturday in Los Angeles, of complications from a rare form of dementia.
Carr was best known for portraying Liesl von Trapp in Rodgers and Hammerstein's 1965 film, in which she performed the song Sixteen Going On Seventeen.
She was a college student when she auditioned for the film, which also starred Julie Andrews and Christopher Plummer.
Carr later wrote a pair of books about her experiences, Forever Liesl and Letters To Liesl.
The actress went on to star with Anthony Perkins in the Stephen Sondheim television musical Evening Primrose.
Kym Karath, who played Gretl, the youngest of the von Trapp children, was among those leading the tributes on Twitter.