Ritter collapsed on the set of his current TV show, 8 Simple Rules for Dating My Teenage Daughter, and was taken to a hospital where he died from a condition known as dissection of the aorta.
The son of singer-actor Tex Ritter, John Ritter was born on September 17, 1948 and graduated from Hollywood High School and the University of Southern California. He studied acting with Stella Adler and Nina Foch, and at the Harvey Lembeck Comedy Workshop. He appeared in dozens of films (including an acclaimed appearance in 1996's Sling Blade), television series, and TV movies, narrated a number of audio books, and provided the voice of the title character in PBS's Clifford the Big Red Dog.
Ritter made his Broadway debut in The Dinner Party, Neil Simon's 2000 comedy, for which he received the Theatre World Award. His stage credits also include productions of As You Like It, Butterflies are Free, Desire Under the Elms, Forty Carats, J for J, Love Letters, The Glass Menagerie, The Tempest, and The Unvarnished Truth.
He is survived by his wife, actress Amy Yasbeck, and four children: Jason, Carly, Tyler, and Stella.