- The IndyCar Series is examining ways to make the sport safer
- Dario Franchitti and three spectators taken to hospital following a crash in Houston
- Four-time champion Franchitti had surgery on an ankle injury
- Safety improvements have been made to IndyCar chassis since Dan Wheldon's death in 2011
The IndyCar Series is examining ways to make the sport safer after its four-time champion Dario Franchitti and several spectators were injured in a horror crash in Houston.
The Scottish racer suffered concussion and two spinal fractures, and underwent surgery on his right ankle, following a final lap accident at the Grand Prix of Houston Sunday.
An official and two spectators were also taken to hospital for evaluation following the incident.
"IndyCar is thoroughly reviewing the incident," said a statement on IndyCar.com
"Reducing the risks that are associated with racing is one of our highest priorities and receives our constant and on going focus.
"Our thoughts remain with everyone affected by (the) accident."
The crash in Houston came almost two years after British driver Dan Wheldon died during a multi car wreck at the Las Vegas Indy 300.
Just months before his fatal crash in 2011, two-time Indianapolis 500 winner Wheldon had tested the prototype car chassis for the 2012 season.
Following his death, the chassis, designed by Italian company Dallara, was christened the DW-12 in his honor.
In May of last year, Dallara made further significant safety improvements to the chassis.
These steps to improve safety may have helped Franchitti avoid serious injury.
However, following the latest incident, IndyCar is once again reviewing safety for its drivers and fans.