A driver at Woodhull Raceway died after suffering an apparent heart attack.
The medical emergency sparked a crash, which resulted in the serious injury of a track flagger.
According to track officials, the incident happened Saturday night during the last qualifying heat for the NAPA 602 Crate Sportsman.
Art Goodier, a Pennsylvania man, was participating when his car sped out of control and turned toward the infield.
The flagger was identified as Neil Stoddard. He suffered an array of injuries- including eight broken ribs, a concussion, and will require shoulder surgery.
Both Goodier and Stoddard were airlifted to Robert Packer Hospital. Goodier died at the scene, officials said.
State police were leading the investigation.