John Ritter, the beloved TV comic actor who shot to fame as the star of ''Three's Company'' and enjoyed renewed popularity as the star of the current sitcom ''8 Simple Rules for Dating My Teenage Daughter,'' died Thursday after collapsing on the ''8 Simple Rules'' set in Burbank, Calif. He was taken to an hospital across the street from the studio, where doctors were unable to save him because of a ''dissection of the aorta,'' the result of an unrecognized flaw in the heart's main artery, Ritter's publicists said. He was 54.
The son of actor and country singer Tex Ritter, John Ritter was best known for his Emmy-winning role as Jack Tripper, the stumbling roommate of two California babes on the 1970s ABC sitcom ''Three's Company.'' When that show went off the air after eight seasons, he became the king of the TV guest stars, playing memorable walk-ons on countless shows and recurring characters on ''Anything But Love,'' ''Dave's World'' and ''Ally McBeal.''
Ritter also acted in many movies (winning acclaim in supporting roles in ''Sling Blade'' and ''Tadpole'') and starred in other TV series (''Hooperman,'' ''Hearts Afire''), but with nothing like his Jack Tripper level of popularity until ''8 Simple Rules'' debuted in 2002. Playing Paul Hennessy, father of two nubile teens (in effect, he'd become ''Three's Company'''s bluenose landlord, Mr. Roper), he gave ABC one of its few solid hits in recent years. The show was expected to be a tentpole for the network this year. ''All of us at ABC, Touchstone Television and The Walt Disney Company are shocked and heartbroken at the terrible news of John's passing,'' the network said in a statement. ''Our thoughts and prayers are with his wife and children at this very difficult time.'' Ritter is survived by his second wife (and occasional costar), Amy Yasbeck, their daughter, and three children from his first marriage, including ''Freddy vs. Jason'' actor Jason Ritter.