 There were a trio of celebrity deaths over the weekend. So you're Brandon's sister, huh? Yeah, I'm Brandon's sister. Castmates are mourning the loss of Beverly Hills 90210's Shannon Doherty, who'd been battling cancer. She was 53. Fitness fanatic Richard Simmons died the day after his 76th birthday, and Dr. Ruth Westheimer gone at the age of 96. Deborah Rodriguez, CBS News.