Some sad news out of Hollywood: Harold Ramis, an actor and director who is best known for his work on the 1980s classic Ghostbusters films, has died in Chicago today at the age of 69 years old.

According to Fox News, the Animal House co-writer suffered from a rare autoimmune disease called autoimmune inflammatory vasculitis, which causes swelling in the blood vessels. He died, according to a statement from his representative, as a result of complications of the disease, surrounded by his family.

"His creativity, compassion, intelligence, humor and spirit will be missed by all who knew and loved him," his agent said in a written statement.

His best-known film acting roles are as Egon Spengler in Ghostbusters (1984) and Russell Ziskey in Stripes (1981), both of which he co-wrote. As a writer/director, his films include the comedies Caddyshack (1980), National Lampoon's Vacation (1983), Groundhog Day (1993), and Analyze This (1999). Ramis was the original head writer of the television series SCTV (in which he also performed), and one of three screenwriters for the film National Lampoon's Animal House (1978). Ramis's films have influenced subsequent generations of comedians and comedy writers. Filmmakers Jay Roach, Jake Kasdan, Adam Sandler, and Peter and Bobby Farrelly have cited his films as amongst their favorites.

Judd Apatow, too, has cited Ramis's work as amongst his favorites, and in fact produced Ramis's last work, Year One, in 2009. "When I was 15, I interviewed Harold for my high school radio station, and he was the person that I wanted to be when I was growing up," he said. "His work is the reason why so many of us got into comedy. We grew up on 'Second City TV' and 'Ghostbusters,' 'Vacation,' 'Animal House,' 'Stripes,' 'Meatballs' (which Ramis co-wrote); he literally made every single one of our favorite movies."

His most recent work, according to the Chicago-Tribune, was directing episodes of The Office.

Ramis is survived by his wife, Erica Mann Ramis, his three children, and his two grandchildren.