NASCAR champion Tony Stewart said Friday the mid-August fatal accident involving Kevin Ward Jr. changed his life forever.

Stewart's car struck and killed Ward on a dirt track up upstate New York nearly three weeks ago. Ward's car was bumped by Stewart's one lap prior.

Stewart spoke Friday about incident, but took no questions as the accident is still under investigation.

"This is something that will affect my life forever," he said. "This is a sadness and a pain I hope no one has to experience in their life."

Stewart hasn't raced since the incident in a move he said was out of respect for the Ward family. He's expected to return to the track Sunday at the Atlanta Motor Speedway for the Oral-B USA 500.