Art and Experience: Kathryn Trosper Popper, who was the last living cast member of Citizen Kane, died Sunday according to her son, Joe Popper. She was 100.

Trosper, who played the inquiring photographer who asks, “What’s Rosebud?” in the 1941 film, died at her home in New York City.

In addition to acting, Trosper was director Orson Welles’ longtime personal assistant, working with him in the Mercury Theater division at RKO.

Trosper famously defended the filmmaker upon the release of Pauline Kael’s essay “Raising Kane,” in which Kael argued that screenwriter Herman J. Mankiewicz was the actual writer for Citizen Kane, but Welles had affixed his name on the script.

“Then I’d like to know what was all that stuff I was always typing for Mr. Welles!” said Trosper in Welles’ defense. Kael never interviewed Trosper, who had worked on the film from its rough draft stages to its completion, and the essay was later discredited when Welles’ contributions to the screenplay were documented.

Born in Wyoming on March 18, 1915, Trosper later moved with her family to California, where she received a scholarship to USC at 16.

She then made her way in the film world at both MGM and RKO.

Trosper said in a video interview with NewsBeat Social last year that she was both an actress and an assistant on the set of Citizen Kane. “I would just drop my notebook and run on the set,” the actress recalled.

Her brother, Guy Trosper, became a screenwriter and producer, writing the screenplays for such films as Birdman of Alcatraz (1962) and The Spy Who Came in From the Cold (1965).

At a CIO convention in Boston in 1942, she met her husband, Martin Popper, who was the co-chief defense counsel for the Hollywood Ten. He defended Dalton Trumbo and John Howard Lawson, who were convicted in 1950 of contempt of Congress for refusing to declare whether they were Communists. In 1961, Popper himself was convicted of the same offense.

Trosper is survived by son Joe, daughter Laura, five grandchildren and five great-grandchildren.