Harold Ramis, the U.S. writer-actor-director behind such classic comic films as Caddyshack, National Lampoon's Animal House, and Groundhog Day, has died at the age of 69.

A spokesman for the talent agency that represented him said Ramis passed away Monday in his hometown of Chicago from an autoimmune disease.

Ramis broke into show business in 1969 as a member of the Chicago-based improvisational comedy troupe Second City, where he performed with the late John Belushi, Dan Ackroyd and Bill Murray, all of whom became comedy stars during the 1970s and 80s. Ramis would later become a writer and performer on the Canadian-based sketch comedy show SCTV.

His collaboration on the screenplay for National Lampoon's Animal House, the 1978 hit that starred Belushi as a member of a wild college fraternity, launched his Hollywood career. Ramis made his directorial debut two years later with the movie Caddyshack, which starred Murray as the strange groundskeeper of an elite country club.

Ramis went on to write and/or direct other popular comedies, including Ghostbusters, Stripes, and Analyze This, many of them starring Murray.