The family of John Ritter (search) has filed a wrongful death lawsuit against a Burbank hospital, accusing it of negligence in the 54-year-old actor's death last September.

Ritter's wife, Amy Yasbeck, (search) and his four children, including actor Jason Ritter, filed the claim in Los Angeles County Superior Court last Friday.

Ritter died Sept. 11, 2003 of a tear in his aorta, the result of an undetected heart problem.

The suit, first reported by the entertainment news show "Extra," also names the medical staff of Saint Joseph's Medical Center.

The family alleges the hospital and medical staff were negligent and careless in their examination, diagnosis and treatment of Ritter's symptoms and is requesting unspecified damages.

The suit alleges when Ritter was misdiagnosed as having a heart attack when arrived at the emergency room, complaining of chest pain, nausea and vomiting.

The actor was a master of sitcom silliness who ruled TV comedy with "Three's Company" and rediscovered success 25 years later with "8 Simple Rules ... For Dating My Teenage Daughter."