Multiple lightning strikes occurred behind the racetrack's grandstands and outside one of the gates as fans were leaving, Pocono spokesman Bob Pleban said. It wasn't immediately clear how many of the fans were actually struck by the lightning itself or were injured by related jolts.
"Unfortunately, a member of our raceway family here, a fan, has passed away," Pocono President Brandon Igdalsky said in announcing the death. He provided no details about the victim but expressed condolences to his family.
The victim was in or near his car in a parking lot after the race had ended when lightning struck the car, Monroe County Coroner Bob Allen said. Bystanders performed CPR on the man, who had gone into cardiac arrest, until paramedics arrived, Allen said. They took him to the track's medical facility, where efforts to revive him failed. He was pronounced dead at a hospital.
Allen would only identify the victim as a 41-year-old Pennsylvania man, saying his family had not yet been notified.
The Pennsylvania 400 was called because of storms, with 98 of the 160 scheduled laps completed. As the storm approached, the track posted messages on its Twitter page to more than 22,000 followers near the end of the race encouraging fans to "seek shelter as severe lightning and heavy winds are in our area."
The attendance was estimated by the track at 85,000. Public address announcements were made before the storm and the end of the race for fans to take shelter and evacuate the grandstands, Pleban said.
Racetrack officials were reviewing the logs of when the announcements were made, he said. There was no order to evacuate the track premises.
Jeff Gordon, who won the race, said at a post-race news conference that he could hear a huge crack as he walked down the pit road during the storm. "You could tell it was very close," he said. "I mean, that's the thing that's going to take away from the victory, is the fact that somebody was affected by that."
One person remained hospitalized in critical condition at Lehigh Valley Hospital Center, Pleban said. Three people were taken to hospitals with minor to moderate injuries, and five others were treated on the scene, he said.
"We are deeply saddened that a fan has died and others were injured by lightning strikes following today's race at Pocono," NASCAR spokesman David Higdon said. "Our thoughts are with them as well as those affected by this unfortunate accident."