It was big news in our town, because the high school kid died at a practice. The school had medical staff on hand during games, but no one thought the kids were doing anything dangerous at practice. So by the time they got medical staff to him, he couldn't be resuccitated. All the schools, at least in our league, changed the rules so medical staff was also available at practices. It didn't have to be a doctor, just someone capable of doing CPR.

This is apparently where the "ninja warrior death stroke" legend comes from. Where ninja's were supposed to be able to strike their opponent in the chest and kill him instantly.