Losing colleagues under tragic circumstances is something Dr. Eugene Rhee has become accustomed to. All told, the San Diego-based doctor was personally acquainted with four urologists shot while on the job since 1999. Two lost their lives. "I have a friend who's a Navy SEAL," Rhee said. "This is a guy who has been to war. He told me that none of his colleagues have ever been shot. Well, four of mine have been." Rhee, the former president of the California Urological Association and current physician at Kaiser Permanente in San Diego, said he has often felt threatened while on the job. And the loss of two colleagues, with two more wounded, has reinforced the idea that something is wrong.