Clifford, RIP

Well, here's a really sad way to start the day -- with the news that John Ritter collapsed on the set of his sitcom and died of an undiagnosed heart ailment. Ritter is best-known, of course, as the star of the old "Three's Company" and the new "8 Simple Rules for Dating My Teenage Daughter," but in our house he was best-loved as the voice of Clifford, the Big Red Dog on PBS. My daughter and I did enjoy watching "8 Simple Rules" together last season, and whether that show continues without its dad or goes out of production, I'm going to have some explaining to do -- and when Clifford's voice changes, too. I think this may actually be my kids' first celebrity death. Not a happy landmark.