 This was a grim weekend as we've lost several celebrities. Beverly Hills 90210 star Shannon Doherty has died. Doherty, who lost her battle with breast cancer, was 53. James Sicking of Hill Street Blues has died. His publicist says that Sicking died of complications from dementia at age 90. Fitness guru Richard Simmons has died. His publicist says Simmons died a day after his 76th birthday.