American actress Heather Menzies-Urich, who played one of the von Trapp children in the iconic 1965 film The Sound of Music, has died; Menzies-Urich was 68-years-old.
Menzies' son Ryan Urich told US media his mother had been diagnosed with glioblastoma multiforme about a month ago.
Glioblastoma is one of the most aggressive brain cancers; Urich said his mother's health had declined rapidly in the wake of the diagnosis.
Urich, Menzies-Urich's son by the actor Robert Urich, said his mother died surrounded by family at home in Canada.
"She was an actress, a ballerina and loved living her life to the fullest," Urich said.
"She was not in any pain but, nearly four weeks after her diagnosis of terminal brain cancer, she had enough and took her last breath on this earth at 7.22pm."
Though Menzies-Urich had a diverse acting career, the role with which she remained associated her entire life was that of Louisa von Trapp, the 13-year-old daughter of Captain Georg??? von Trapp (Christopher Plummer) in the film adaptation of The Sound of Music.
In the film's iconic scene where aspiring nun Maria (Julie Andrews) is introduced to her seven charges, Menzies-Urich's Louisa is remembered for attempting to impersonate her younger sibling, Brigitta.
The character of Louisa was based on the real-life Maria Franziska von Trapp, the second eldest daughter of the real-life Georg von Trapp; Maria Franziska died in 2014, aged 99.
The Sound of Music, in which Menzies-Urich appeared, was based on the true account of the family's life in Austria and their flight in the face of German occupation to the United States of America.
Menzies-Urich won the role in The Sound of Music at the age of 14 not long after her family moved from Toronto in Canada to Los Angeles, to help her pursue a career in acting.
Though she worked after The Sound of Music, Menzies-Urich never equalled that film in terms of cultural impact or enduring memory.
Her later credits include the genre horror films Sssssss (1973) and Piranha (1978) and, on television, series such as Marcus Welby, M.D., Bonanza, Love, American Style and The Bob Newhart Show.
In the mid-1970s, while filming a television commercial, Menzies met actor Robert Urich; the pair later married and they had three children, Ryan, Allison and Emily.
After Urich's death in 2002 from synovial sarcoma, a rare form of cancer, Menzies-Urich created the Robert Urich Foundation and devoted much of her time to raising money for it.
"After my husband lost his battle on April 16th, 2002, I vowed that I would make it my life's mission to continue to fight for his dream and vision: a world where the word cancer is simply a memory of war we have won," she said.
Menzies-Urich's later television credits included the short-lived TV reboot of the science fiction hit film Logan's Run.
Menzies-Urich's on-screen sister, Kym Karath, who played Gretl, said she was "filled with infinite sadness" upon learning of Menzies' death.
"My precious friend and [Sound of Music] sister Heather Menzies passed away this evening," she said. "[I am] devastated."
Ted Chapin???, the president of the Rodgers and Hammerstein Organisation, which owns the rights to The Sound of Music, said "we are all lucky to have known her, and she will happily live on in that beautiful movie. We will miss her."
Dan Truhitte???, who played the Nazi-sympathising Rolf in The Sound of Music, said it was "such a great sorrow to lose Heather Menzies Urich.
"She was a joy during filming, such a warm smile, and such a talent and I know she is now with her husband, Robert Urich. Aufwiedersehn for now, Heather," he said.
Menzies-Urich's on-screen elder sister, actress Charmian Carr, who played the eldest daughter Liesl, died in 2016.
Menzies-Urich is survived by three children and eight grandchildren.