Actor and director Harold Ramis, best know for playing Egon Spengler in Ghostbusters, has died aged 69.
He had been suffering from a rare blood disease known as autoimmune inflammatory vasculitis, his family said in a statement.
Ramis achieved worldwide fame in the 80s, playing oddball scientist Egon in the two Ghostbusters movies.
He was also an accomplished writer and director, with credits that included Caddyshack, National Lampoon's Vacation and the hugely popular Groundhog Day.
CLICK HERE FOR THE FILMS OF HAROLD RAMIS
His comedy career began in earnest in 1969, when he joined 'Chicago's Second City' improvisational comedy troupe.
He soon found work on television, before graduating to movies with the scripts for Animal House, Meatballs and Caddyshack, making his directorial debut with the latter.
In 1984 Ramis hooked up with Dan Aykroyd to write Ghostbusters, which became a huge critical and commercial hit. The pair also co-wrote and starred in the 1989 sequel.
Two years later, Ramis directed Groundhog Day, largely regarded as one of the greatest comedies of all time.
A disagreement on the Groundhog Day set caused Ramis and star Bill Murray to fall out, ending a relationship that had spanned six movies, each one a commercial hit.
According to the Chicago Tribune, Murray was one several friends who visited Ramis prior to his passing.
Ramis' last big screen directing job was the 2009 comedy, Year One. He also directed four episodes of the American version of The Office, the last of which in 2010.
He is survived by his wife Erica, two children and two grandchildren.
"Sad to hear my friend Harold Ramis passed away. A brilliant, funny, actor and director. A wonderful husband and dad. Big loss to us all." Billy Crystal
"If you're my age and got into comedy, Harold Ramis was one of the reasons. Life is fast and over too soon." - Zach Braff
"If a Twinkie represents amount of grief I feel when someone dies, Harold Ramis' death would be a Twinkie 35 feet long weighing 600 pounds." - Patton Oswalt
"Harold Ramis. Funny, gracious, kind hearted. A joy to have known you." - Steve Carrell
"RIP Harold Ramis - A creator of often outrageous comedy yet always laced with heart. If u don't recognize his name. Look it up!" - Ralph Macchio
"Harold Ramis was a brilliant, shining example for every comedy writer hoping to achieve excellence the field" - Seth MacFarlane
"Was honored to have gotten to work with Harold Ramis, the Buddha of Comedy. Brilliant, humble, radiant. We've lost an icon. #GroundhogDay" - Rainn Wilson
"No, no, not Harold Ramis. Worked for him years ago. He was the real deal. Growing up, his work changed my life. He will be missed." - Jon Favreau
"Caddyshack. Griswalds. Egon Spengler was always my favorite Ghostbuster. Genius. My condolences to Mr. Ramis's family." - Justin Timberlake
"NOOOOOOOOO! RIP Harold Ramis. All my heroes are leaving the world #EgonSpengler #Ghostbusters" - Noel Clarke
"Just got off the plane to find out Egon is gone! RIP HAROLD RAMIS, director of one of my favorite flicks, VACATION" - Kevin Smith
"Stunned and saddened to hear of the death of Harold Ramis. A comedy hero." - Stephen Fry