Three-time NASCAR champion Tony Stewart will not race as scheduled today after a tragic night on the track in New York.

Stewart hit and killed Sprint car driver Kevin Ward Jr. Video from last night's race shows Ward Jr. walking on the dirt track after exiting his car following a spin out. He appears to be looking to confront Stewart when he's suddenly struck by his car.

Police say Stewart was unhurt and is cooperating with the investigation. Stewart was scheduled to compete in today's NASCAR race at Watkins Glen, but has since pulled out.