By: M.L. Stein A SACRAMENTO BEE carrier who survived 10 years in a Vietnamese communist "reeducation" camp was stabbed in the back and killed while on his route. Sheriff's deputies said the victim, Tu Van Trieu, 50, was not robbed, and they had no firm suspects. The only possible clue was a report that two men in a pickup truck were seen nearby about the time of the stabbing. Trieu, a former South Vietnamese army captain who emigrated with his wife and three children in 1991, was described by Bee circulation director Gene Czarny as an exemplary carrier. "This is a tragic and scary thing," Czarny said. "There is no way to protect anyone against a random killing, which this seems to be." Trieu had completed his route when he was found about 6:45 a.m. in an apartment house passageway open to the street. His wallet was intact. The Bee reported that a resident of the apartment complex heard Trieu's cries about an hour after the stabbing. The resident speculated that others in the building heard him earlier but thought he was a drunk. Trieu died at a hospital l6 minutes after arriving by ambulance. In what Czarny described as "a family operation," Trieu handled four paper routes for the Bee since June 1993, and his two sons have two routes each. Trieu was studying English and hoped to return to computer work, since he had experience in Vietnam. The Bee offered a $5,000 reward for information leading to the conviction of the killer. The newspaper also pledged $5,000 toward a trust fund set up by the Sacramento Vietnamese Coalition for Trieu's family. Meanwhile, the Bee said, Trieu's wife and sons were pitching in to take over his routes.