We know more than ever about concussions, the permanent brain damage of chronic traumatic encephalopathy and the other physical risks of football.
Yet so far this year, at least 19 students have died playing football, according to the University of North Carolina's National Center for Catastrophic Sport Injury Research.
Though participation is slowly declining, football is still the country's most popular high school sport. Over a million high schoolers played last season.
Researchers at UNC have been tracking football-related deaths since the 1960s.