Tragic accidents claim lives of teen equestrians during competitions.

A 15-year-old equestrian, Hannah Serfass, died during a competition in Florida after a horse knocked her off and then fell on her head. The horse tripped and suffered a rotational fall, causing the rider to topple forward and off the horse in the same direction and onto the ground. The accident will be reviewed by the federation "to learn what we can do to minimize risk and increase safety in equestrian sport," it said.