NASCAR Champion Tony Stewart Hits and Kills Sprint Car Driver Kevin Ward Jr. [VIDEO]

In a horrific collision, NASCAR driver Tony Stewart hit and killed 20-year-old Sprint Car driver Kevin Ward Jr., who was walking on a racetrack in upstate New York on Saturday night (8/9), authorities said. Ontario County Sheriff Philip Povero said Ward was pronounced dead on arrival at an area hospital.

Povero is not treating the investigation as criminal case and reported Stewart is being "fully cooperative" and appeared "very upset" over the incident.