Susan Sontag died at age 71

Susan Sontag, the author, activist and self-defined "zealot of seriousness" whose voracious mind and provocative prose made her a leading intellectual of the past half century, died Tuesday. She was 71.

Sontag died Tuesday morning, officials at Memorial Sloan-Kettering Cancer Center said. She had been treated for &to=http:// ' target=_blank>breast cancer in the 1970s.

Sontag called herself a "besotted aesthete," an "obsessed moralist" and a "zealot of seriousness", says ABC News.

She was the author of 17 books, including a novel, "In America," that won a U.S. National Book award, and a lifelong human rights activist.

Her work has been translated into more than 30 languages. Among her best known works was a 1964 study of homosexual aesthetics called "Notes on Camp."

Fellow author and friend Salman Rushdie described her as "a great literary artist, a fearless and original thinker, ever valiant for truth" who insisted "that with literary talent came an obligation to speak out on the great issues of the day."