HOUSTON -- Four-time IndyCar Series champion Dario Franchitti was injured in a multicar accident near the end of Sunday's Grand Prix of Houston.

According to IndyCar medical director Dr. Michael Olinger, Franchitti was awake and alert at the scene. He was transported by ground to Memorial Hermann-Texas Medical Center, where it was determined he sustained a concussion, a spinal fracture that will not require surgery, and a fracture to his right ankle. He underwent surgery on the ankle.

Safety team members work to remove Dario Franchitti from his car after a crash during the second IndyCar Grand Prix of Houston on Sunday. AP Photo/Juan DeLeon

A considerable amount of debris from the crash, including a wheel and tire assembly, flew toward a spectator area near Turn 5 of the 1.7-mile temporary track that winds through Reliant Park.

Houston Fire Department spokesman Ruy Lozano said at least 13 people were treated for minor injuries, with two transported to Memorial Hermann. One of those transported was IndyCar timing and scoring worker Kim Tyger, whose injuries were called "very minor" by the sanctioning organization.

Franchitti was running in 11th place, four spots behind Takuma Sato, when Sato's car lost grip and slid on Lap 88 of 90. Several cars got past the Japanese driver, but he veered into the path of a fast-closing Franchitti, whose car was launched into the steel catch fence that lines the course.

The accident occurred at one of the fastest parts of the Houston course, on a blind right-hand bend that leads into a favored passing zone at Turn 6.

Franchitti's car shredded a large section of fencing as it spun airborne before landing on the track. E.J. Viso's car was also swept into the accident.

"He's talking," Franchitti team owner Chip Ganassi said in an interview with NBC Sports Network. "His ankle is a little sore and his back is a little sore.

"He's gonna take a trip to the hospital, that's for sure. But he's OK."

Target Chip Ganassi Racing said Monday that Franchitti will remain in Houston for a few days and then be taken to Indianapolis for further evaluation. The team also said Franchitti thanked his fans for their support.

The final two laps were run under caution, with Team Penske's Will Power earning the win over Franchitti teammate Scott Dixon.

Dixon's second-place finish gave him a 25-point lead in the IndyCar Series standings heading to the Oct. 19 season finale at Fontana, Calif. Helio Castroneves, who entered Sunday's race as the points leader, suffered gearbox problems and finished 23rd.