Emmy-winning actor Robert Urich, best known for playing tough detectives in TV's Vega$ and Spenser: For Hire, died Tuesday of cancer. He was 55. Urich died at a hospital in Thousand Oaks, Calif., surrounded by family members and friends. In 1996, Urich announced that he was suffering from synovial cell sarcoma, a rare cancer that attacks the body's joints. A memorial service was scheduled for Friday in Los Angeles.