(CNN) -- Three-time Indianapolis 500 winner Dario Franchitti was involved in a serious crash that hurt 13 spectators Sunday during the Grand Prix of Houston.
The wreck occurred in the last lap of the race when Franchitti's car was bumped by Japanese driver Takuma Sato, propelling the car airborne into the protective fencing. The car spun multiple times against the fence, sending pieces 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, 40, appeared to be moving after the wreck, but his condition was not immediately known. His team owner told NBC Sports, which aired the race, that Franchitti was sore, but awake and alert.