WATKINS GLEN, N.Y. (AP) — A spokesman for Tony Stewart calls the death of a fellow driver he struck and killed at an upstate New York dirt track a “tragic accident.”

The three-time NASCAR champion hit Kevin Ward Jr. on Saturday night as Ward walked toward Stewart’s car following an on-track incident at Canandaigua Motorsports Park.

In a statement released Sunday morning, a representative for Stewart says, “our thoughts and prayers go out to his family and friends.” The statement says Stewart’s team is still trying to sort through the details of the accident.

Stewart did not race Sunday in NASCAR’s Sprint Cup race at Watkins Glen.