An assistant football coach at Yucca Valley High School was fired by the school board Tuesday. In July, a 17-year-old boy arrived at football practice after the helmets had been locked away, and James Tyson told him to practice without a helmet. During practice, the boy collided with a teammate and suffered a concussion. He said he was told to sit on the sidelines without getting any medical attention until his father arrived and took him to a hospital. The school board refused to comment any further on Tyson’s dismissal, saying it was a personnel issue.