NASCAR driver TONY STEWART struck and killed another driver on foot during a sprint car race on a dirt track in upstate New York on Saturday night.  And it seems like some degree of road rage was a factor.

Kevin Ward Jr. via Associated Press

The other driver was 20-year-old Kevin Ward Jr..  He was racing side-by-side with Stewart, when Stewart cut him off, forcing him into the wall and causing him to spin out.

Video footage shows Ward getting out of his car and walking on the live track toward the cars.  As Stewart came back around, Ward tried to CONFRONT him,   and Stewart's car swerved into him.

Ward was struck and dragged several feet, before his body was thrown about 50 feet down the track.  When it came to a stop, he was completely motionless.  Emergency personnel rushed in immediately, but it was too late.

Some people are saying that Stewart either INTENTIONALLY hit Ward, or that he wanted to scare him by kicking up some dirt around him.

His motor revved up just before he hit him, so he may have also been trying to show him up by SPEEDING past him.

Either way, Stewart didn't try to AVOID Ward, assuming he saw him in the first place.  It was nighttime, and the track was dimly lit.

The sheriff investigating the incident said there's no evidence of "criminal intent."  He also said Stewart has been cooperating with the investigation.

Stewart backed out of Sunday's NASCAR Sprint Cup Series race after the accident.  In a statement, he said, quote, "There aren't words to describe the sadness I feel about the accident that took the life of Kevin Ward Jr.

"It's a very emotional time for all involved, and it is the reason I've decided not to participate in today's race.  My thoughts and prayers are with his family."

(Here's a clip that shows Stewart hitting him about 35 seconds in.  WARNING:  The video contains UNCENSORED profanity.  Not to mention the fact that you're watching a man basically get RUN OVER AND KILLED.)

(Here's another video . . . the same warnings apply.)