Wilson appeared to suffer a huge blow to his helmet after race leader Sage Karam crashed in the closing stages of the 500-mile race.

The nose section of Karam’s Chip Ganassi Racing Dallara flew off his car as he hit the outside wall, and then appeared to strike Wilson directly on the helmet. The nose section was sent flying into the air.

Wilson’s car then veered into the inside wall, which he struck. Safety crews immediately rushed to his aid, and he was extracted from his Andretti Autosport machine.

He was taken straight to the helipad via ambulance and stretcher, where a powered-up helicopter was waiting. The sanctioning body has no update on his condition at this time, but confirmed that he suffered a head injury and was transferred to Lehigh Valley Health Network Cedar Crest Hospital in Allentown, Pa.

Wilson's team boss Michael Andretti said: “Our thoughts and prayers are with Justin right now, we just hope he’s OK.”

Wilson's teammate and race winner Ryan Hunter-Reay also voiced his concern, and said he was unaware of the potential for serious injury.

“I saw the trucks around him, they said he was in the ambulance, so I thought he was OK with Sage, but I have no details,” said Hunter-Reay. “He’s my friend first and foremost, and he’s a teammate. It’s a bit hard not knowing anything.”

Karam walked to the ambulance, but has also been transported to a local hospital for a right foot injury.

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