HOUSTON (CNN) -- Three-time Indianapolis 500 winner Dario Franchitti was involved in a serious crash that hurt 13 spectators during Sunday's Grand Prix of Houston, authorities reported.
The wreck occurred in the last lap of the race, when Japanese driver Takuma Sato bumped Franchitti's car, sending it airborne into the protective fencing. The car spun multiple times against the fence, sending shards of debris flying toward the grandstands and shearing off part of its side.
Two of the 13 spectators injured were sent to local hospitals, while the rest were treated at the scene, according to Senior Capt. Ruy Lozano of the Houston Fire Department.
Franchitti, who's 40, appeared to be moving after the wreck, but his condition was not immediately known. Team owner Chip Ganassi told NBC Sports, which aired the race, that Franchitti was sore, but awake and alert.
The Scotland native won Indycar racing's top prize in 2012, 2010 and 2007. He was married to actress Ashley Judd for more than 11 years, but the couple announced they were ending their marriage in January.