Three suspected Los Angeles street gang members were killed and a fourth was injured when the car in which they were riding crashed into a supermarket, authorities said. They were attempting to elude California Highway Patrol officers in a high-speed chase, patrolmen said. DeJohn J. Thomas, 13; Clay Johnson, 15, and Marcel D. Douglas, 17, were killed when their car slid into the market at Redondo and Adams boulevards. An unidentified 15-year-old boy was injured and reported in stable condition at Cedars-Sinai Medical Center. The chase began when officers attempted to stop the car because its headlights were not on. Police said the survivor told his father that he and his friends fled because they had a gun in the car. Officers found bullets but no gun.