A 15-year-old cross-country runner was killed and three other teen-agers were injured by a car that veered off a roadway and slammed into the four joggers, San Jose police said. The front of the car struck two boys, police said, and two girls were clipped by the car's side. Witnesses said three of the runners were hit with such force that they were knocked out of their shoes as they ran near San Jose International Airport. The driver of the car, Drinda Jane Atnes, 45, was being held on three counts of driving under the influence of prescription drugs and one count of vehicular homicide. Robert Perez, a sophomore at Overfelt High School, died at San Jose Hospital of severe head injuries several hours after the accident. The other boy, Carlos Alegria, 14, was in critical condition. The two girls suffered less serious injuries.