Wilson, 37, died following injuries sustained at Pocono Raceway in Long Pond, Penn., IndyCar announced Monday. Wilson started 173 races in the Champ Car and the IndyCar Series from 2004-2015.
LONG POND, PA. - IndyCar driver Justin Wilson was in a coma and in critical condition after sustaining a head injury when he was hit by a large piece of debris that broke off a car Sunday in the crash-filled race at Pocono Raceway.
IndyCar released the information on Wilson's condition Sunday night and said he was undergoing further evaluation at Lehigh Valley Health Network Cedar Crest Hospital in Allentown.
The debris broke off Sage Karam's car when Karam spun into the wall. Wilson's car veered left and directly into an interior wall. Wilson was swarmed by the safety crew and airlifted by helicopter.
"It's just a tough one right now," said Michael Andretti, car owner for Wilson and race winner Ryan Hunter-Reay. "Our thoughts and prayers are with Justin right now. We're going to see. Hopefully, he's OK."
IndyCar had a subdued victory lane and Hunter-Reay was not sprayed with the traditional confetti.
The American said his thoughts were only with Wilson, an extremely popular driver in the paddock who speaks on behalf of his peers regarding safety and competition.
"All I know is that he was unconscious, he was not responding and he was airlifted," Hunter-Reay said. "That's all very bad. I'm very worried right now."
The accident was a grim reminder of the dangers of open-wheel racing. Indianapolis 500 winner Dan Wheldon died in 2011 after his car became ensnared in a fiery 15-car pileup, flew over another vehicle and landed in a catch at Las Vegas Motor Speedway. Wheldon's head hit a post in the fence, and he died instantly.
He was the last fatality in a form of racing that saw drivers Scott Brayton (1996), Tony Renna (2003) and Paul Dana (2006), among others, die after wrecks.
Wilson's wife, Julia, was en route to Pennsylvania from their home in Colorado, while his younger brother, Stefan, also an IndyCar driver, was travelling from Indianapolis.
The race resumed after the Karam and Wilson accident with seven laps remaining and Hunter-Reay picked his way through the field. He passed Juan Pablo Montoya, Takuma Sato and then used a bold inside pass of leader Gabby Chaves to take the lead with five to go.
Chaves then appeared to have an engine failure that brought out the caution with three to go. The race ended under yellow.
Hunter-Reay tried to get an update on Wilson before the race resumed, and again before he climbed from his race-winning Honda.
"I thought Justin was OK the whole time, and I thought he was in the ambulance with Sage heading off to get a routine check," Hunter-Reay said.
Josef Newgarden was second and IndyCar points leader Montoya finished third.
Graham Rahal, who was second in the standings at the start of the race, was involved in an early crash. Montoya's cushion went from nine points to 35 with next Sunday's finale in Sonoma set to decide the title.
The finale is worth double points, and six drivers will head to California in contention for the title.
Hunter-Reay is mathematically eliminated, but picked up his second win of the season in what's been a disappointing year for Andretti and Honda.
Hunter-Reay was one of many who was discussing safety measures --and not his win -- for the open-cockpit series.
"Maybe in the future we can work toward something that resembles a canopy," Hunter-Reay said. "Something that can give us a little bit of protection and still keep the tradition of the sport. Just to be innocent bystander like that and get hit in the head with a nose cone is a scary thought."
The 37-year-old Wilson, a native of Sheffield, England, entered this season without a full-time ride.
He latched on with Andretti and was in the sixth of seven scheduled races with the team. The deal was put together right before the season-opening race in March and initially started as just a two-race agreement at Indianapolis.
Sponsorship was found for another five races as the season progressed, and Wilson finished a season-best second earlier this month at Mid-Ohio.
He said after the race that he raced clean and did not take any risks that would have jeopardized eventual race-winner Rahal because Rahal was part of the championship race and Wilson was not.
Wilson broke a bone in his back at Mid-Ohio in 2011. He missed the final six races of the season and wore a back brace for more than two months as he was restricted from any physical activity. The injury kept him out of the season finale at Las Vegas and the race where Wheldon died.
He broke his pelvis and suffered a bruised lung in the 2013 season finale at Fontana.
Wilson said in 2012 his injuries and Wheldon's death did nothing to change his perspective or make him question his career choice.
"I've had the conversation with Julia - this is what we do, and you try to make the best plans if that ever happens," Wilson told The Associated Press upon his return in 2012. "You've got to know the risks and work out if those risks are acceptable. To me, it's acceptable. But I'm not going to stop trying to improve it.
"All the drivers, this IndyCar, we're always trying to make it safer, but at the end of the day, it's a race car. We're racing hard, we're racing IndyCars and it's fast. When it goes wrong, it can get messy.
Additional updates to Wilson’s condition will be released when available.