Dario Franchitti kept racing after the deaths of friends Greg Moore and Dan Wheldon.
But Thursday, the three-time Indianapolis 500 winner and four-time IndyCar series champ retired after doctors told him it would be too dangerous to continue because of injuries sustained in a crash.
"Racing has been my life for over 30 years, and it's really tough to think that the driving side is now over," Franchitti, who won the 2011 Grand Prix of St. Petersburg, said in a statement released by his team, Target Chip Ganassi Racing.
The Brit did not use the word "retire." But asked on Twitter if he had done so, his ex-wife, actress Ashley Judd, replied: "Yes, with an extraordinary career, legendary achievements, aplomb & style."
Franchitti, 40, broke his spine and right ankle and sustained a concussion Oct. 6 in Houston when his car hit Takuma Sato's car and sailed into a fence. Debris injured 13 fans and one IndyCar official. Franchitti had two surgeries on the ankle.
"If the doctors tell him he should quit, then he should listen," said A.J. Foyt, the only driver with more IndyCar titles than Franchitti with seven. "I'm the opposite and never would listen. But Dario's won a lot of races and championships, so he has a lot to be proud of. My hat's off to him."
After racing in NASCAR from 2007-08, Franchitti thrived upon his return to IndyCar. He won three straight series titles and two Indy 500s. His 31 victories overall are tied for eighth.
Franchitti, one of 10 drivers with at least three Indy 500 wins, always had crossover appeal thanks to an 11-year marriage to Judd, but he also was personable and well-spoken.
"Dario Franchitti has done so much for Target Chip Ganassi Racing," Ganassi said. "But simply put, Dario is a motorsports legend and will be sorely missed on the racetrack by everyone in the paddock and in the stands."
Franchitti defeated Will Power three consecutive years to win the IndyCar championship, and the two developed a rare rivalry for the series.
"We had some real battles out on the track over the last few years," Power said. "And I appreciated how fierce of a competitor he was."
Franchitti's last victory was the 2012 Indy 500, which came seven months after Wheldon's death during a race in Las Vegas. Scott Dixon and Tony Kanaan, also close friends of Wheldon, finished second and third, respectively.
It was a poignant moment for Franchitti, who was too familiar with death in the sport he loved. Moore died in the 1999 season finale at Fontana.
"I'll forever look back on my time racing in CART and the IndyCar Series with fond memories, and the relationships I've forged in the sport will last a lifetime," he said. "Hopefully in time, I'll be able to continue in some off-track capacity with the IndyCar series. As my buddy Greg Moore would say, 'See you up front.' "