Brian Zimmerman, 41, of Moosic, Pa., was killed when he was struck by lightning near his car in a raceway parking lot minutes after Jeff Gordon was declared the race winner. Only one of the nine others who were injured remained hospitalized, and his condition, according to officials at the Long Pond track, has been upgraded from critical to stable.
Some fans have contended on social media sites that there were no warnings, or at least no audible warnings, given to spectators during the closing stages of the race.
Track officials said several such announcements were made - over the public address system and via social media - some while the event was still going on.
"Some fans are saying they heard it early," said track president Brandon Igdalsky. "Some are saying they didn't hear it early. So we're going through all our logs and records."
A NASCAR spokesman said its emergency procedures for such occurrences also were being reviewed.
"Anytime something like this happens, we make sure we look at it again and see if there's anything we should have done different," said David Higdon.
The 21/2-mile track was dry as the storm grew imminent, and even though lightning was forecast, the race continued. That decision was made by track officials, said Higdon.
"[Track officials] need to ensure the safety of the fans up to our expectations," said Higdon. "We need to ensure the safety of the competitors and those who are part of the traveling team that goes to each track."
According to the National Weather Service, a severe- storm warning was issued for the area at 4:12 p.m. NASCAR stopped the race at 4:54 p.m. Zimmerman was struck shortly after 5 p.m. A second strike was reported at 6:35 p.m.
Patrick Kelly, a veteran NASCAR fan from Franklinville, N.J., who attended, said the approach of the storm was no secret.
"Everybody could see it coming," he said. "And everybody had smart phones and could have been checking the weather. At that point, it's just common sense. I didn't hear any announcements, but it seemed to me they were doing what they could to secure the safety of people."
The raceway has set up a memorial fund to benefit Zimmerman and the other victims. Donations to the Pennsylvania 400 Memorial Fund, Pleban said, can be made at any PNC Bank.
"At the end of the day, it's Mother Nature, and it's very difficult for anyone to take responsibility and say, 'Hey, we should have done this or should have done that,' " driver Carl Edwards said of the Pocono event during a Tuesday interview session at Martinsville (Va.) Speedway.
"It's something I would have never expected. I walked right out of my hauler and into my motor home in the middle of that rainstorm and, ignorantly, I didn't think about the dangers that were there. I think we all take that stuff a little too lightly."
Contact staff writer Frank Fitzpatrick at 215-854-5068, firstname.lastname@example.org, or on Twitter @philafitz. Read his blog, "Giving 'Em Fitz," at www.philly.com/fitz.
This article contains information from the Associated Press.