Eight of 25 children headed for a Riverside junior high school were slightly injured when a truck rig slammed into their school bus, authorities said. The injured youngsters, ranging in age from 12 to 14, were taken to three hospitals, but Riverside County Fire Capt. Gary Vanderhorst said all the injuries were minor. Truck driver Carter McGhee, 30, and a passenger, John Rossi, 24, were taken to Riverside General Hospital, where Rossi was treated and released. McGhee was in good condition with undisclosed injuries. The children were aboard an Alvord School District bus headed for Arizona Intermediate School.