South Korean Captain Kills 6, Slays Himself1 SEOUL, Korea — — ASouth Korean Army captain shot and killed six fellow officers and noncoms and then himself last Thursday night in a mysterious g u n f i g h t at Hongchun, 60 miles east of Seoul.A preliminary investigation showed the captain. Cho Sang Kook had just been relieved of his command, and his successor was his first victim. The Army sent investigators to the scene.