Relatives of the late John Ritter have filed a wrongful death and malpractice suit against the doctors and the Burbank, Calif., hospital where the 54-year-old actor died last year. According to court papers, Ritter's wife, Amy Yasbeck, and children, Carly, Tyler, Jason and Stella allege that doctors misdiagnosed him as having a heart attack when he actually died of a tear in his aorta. The suit seeks unspecified damages.