British IndyCar driver Justin Wilson has died from a head injury sustained during a race at Pocono Raceway in Pennsylvania.
Wilson, 37, a former Formula One driver and seven-time winner in IndyCar racing, had been in a coma after he was hit on the head by a piece of debris that had broken off another car on Sunday.
His car veered into a wall at the track after he was hit by the debris from the car of Sage Karam on the circuit.
Karam had been leading the race when his car spun out on lap 179 of the 200-lap race and hit a wall, sending pieces of the car airborne.
He was sent to hospital with heel and wrist injuries but was released on Sunday.
"I can't find the proper words to describe the pain and sympathy I feel for Justin and his family," Karam said in a statement on Twitter, followed by the hashtag #RIPJustin.
IndyCar officials paid tribute to the driver.
"This is a monumentally sad day for IndyCar and the motorsports community as a whole," Mark Miles, chief executive officer of Hulman & Co, the parent company of IndyCar and Indianapolis Motor Speedway, said in a statement.
"Justin's elite ability to drive a race car was matched by his unwavering kindness, character and humility - which is what made him one of the most respected members of the paddock," Miles added.
Wilson's family said in a statement that he was a "loving father and devoted husband, as well as a highly competitive racing driver who was respected by his peers".
He is survived by a wife and two daughters.
Wilson was the first IndyCar driver to die following a race accident since fellow Briton, Dan Wheldon, was killed in a crash in Las Vegas in October 2011.