From AWN Headline News:
Flintstones Composer Will Schaefer Passes Away
July 06, 2007

Will Schaefer, the composer on many Hanna-Barbara series, such as THE FLINTSTONES, THE YOGI BEAR SHOW and SCOOBY-DOO, WHERE ARE YOU!, passed away from cancer on Saturday, June 30, 2007, in Palm Desert, California. He was 78 years old.
Schaefer also composed music for Walt Disney Studios and for Disneyland attractions. Details and the full story here: AWN Headline News