NASCAR fans at Pocono Raceway were advised over public address systems and through social media to take cover when lightning and heavy rain hit the track near the end of the race.
The warnings weren't enough to avoid tragedy at the track on Sunday.
Lightning strikes at Pocono after a rain-shortened NASCAR race killed one fan and injured nine others, one critically, racetrack officials said.
The Monroe County coroner said Monday that Brian Zimmerman, of Moosic, Pa., died as he stood near his car in the parking lot.
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.
Igdalsky later posted on Twitter, ''My family and I are praying for all those that were involved in the lightning strikes. ... Difficult evening for all.''
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.
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.''