Danica Patrick IndyCar
Danica Patrick, 29, will leave IndyCar to race full-time in NASCAR. Reuters

Danica Patrick ended her IndyCar racing career on Sunday, the same day that Dan Wheldon was killed in a horrific crash.

Patrick, 29, one of the best-known and most popular racers in the country, plans to compete full-time in the NASCAR Nationwide Series, in which she has previously competed part-time.

She made the decision to increase her chances of winning, fellow racers said.

It is a very tough move, but one advantage Danica will have is she'll be driving good cars, Dario Franchitti, who has raced in both IndyCar and NASCAR, told ESPN. That will be a massive help for her.

Her fans and fellow racers will be sad to see her go.

Danica did bring, I think, new fans to our sport, and hopefully those fans aren't here only because of Danica, Michael Andretti, Patrick's current team owner, told ESPN. I'm sure she brought fans that normally wouldn't have watched it but now have become fans of IndyCar racing.

Another racer, Davey Hamilton, added that her move to NASCAR could have a significant effect on IndyCar's popularity.

I hate to see her go, Hamilton said. She's probably going to take away fans, and we can't afford that.

Patrick: A Trailblazer

Patrick's career has been extremely impressive. She is the only female driver ever to win an IndyCar event; she won the Japan 300 in 2008. She was also the rookie of the year in 2005.

Her final IndyCar race was the Izod IndyCar World Championships season finale in Las Vegas on Sunday, but it was marred by the devastating crash that killed Wheldon. Patrick narrowly missed the 15-car pileup.

It was like a movie scene which they try to make as gnarly as possible, Patrick said in a live interview on ABC after the crash, but before Wheldon's death had been announced. It was debris everywhere across the whole track. You could smell the smoke. You could see the billowing smoke on the back straight from the car. There was a chunk of fire that we were driving around. You could see cars scattered.

After hearing that Wheldon had died, Patrick tweeted, There are no words for today. Myself and so many others are devastated. I pray for suzi [Wheldon's wife] and the kids that god will give them strength.