Dario Franchitti: IndyCar champion leaves hospital after crash

Four-time IndyCar champion Dario Franchitti has been released from hospital but faces further surgery after his high-speed crash at the Houston Grand Prix on Sunday.

The Scot, 40, broke two vertebrae in his spine, two ribs and an ankle.

His car flipped into the air following a final-lap collision with Takuma Sato, with at least 13 spectators injured by debris that flew over safety fencing.

Franchitti said he was "overwhelmed by the outpouring of support".

In a statement issued through IndyCar, the driver, who will need a second operation on a surgically stabilised right ankle, said he would be watching his Chip Ganassi team-mates Scott Dixon of New Zealand and Alex Tagliani of Canada on television.

"I look forward to watching Scott, Alex and the Target team next weekend on television, and will be pulling for them as they go for another championship."

He added: "I'm thankful to have such a great family and such wonderful friends and fans. Thanks to everyone at the hospital and the track who took such good care of me during my stay in Houston."

A statement from IndyCar said the three-time Indianapolis 500 winner would now be transported to Indianapolis, where his condition would be re-evaluated.

During the second race of IndyCar's Grand Prix of Houston double-header on Sunday, Franchitti's car hit the back of Sato's and was propelled into the air and into the fence.

His vehicle broke into several pieces but did not catch fire.

Former Formula 1 driver Sato said his car "caught the marbles" - chunks of rubber that come off the tyres and lie on the track - before brushing the wall and losing momentum.

An IndyCar official and 13 spectators were also hurt by flying debris from the three-vehicle smash that also involved Venezuelan EJ Viso's car. Both Viso and Sato were able to walk away.