Updated

Actor John Ritter (search) was remembered by his family and close friends at a private service Monday, four days after his sudden death.

Ritter's publicist, Lisa Kasteler (search), did not release details of the service. She said a public memorial was being planned and Ritter's friends and colleagues will pay tribute to him in an ABC News special.

"A Life of Laughter: Remembering John Ritter," an hour-long program anchored by Diane Sawyer (search), will air at 8 p.m. EDT Tuesday.

Those scheduled to be part of the special include Suzanne Somers and Joyce DeWitt, who costarred with Ritter in the 1977-84 sitcom "Three's Company," and Katey Sagal, his co-star on the ABC sitcom "8 Simple Rules for Dating My Teenage Daughter."

Ritter, 54, died last Thursday after suffering a tear in his aorta. He was stricken while on the set of "8 Simple Rules."

ABC was weighing the future of the show, which was to start its second season Sept. 23 and was seen as a key part of the network's effort to rebound in the ratings.