Sonoma, Calif. ? Driver Will Power of Team Penske broke two vertebrae in his lower back and sustained a concussion Saturday after crashing into Nelson Philippe of Conquest Racing during a practice session for the Indy Grand Prix of Sonoma.

Philippe also sustained a concussion along with an open fracture to his left foot that required surgery.

The 28-year-old Power, the former road course specialist who finished fifth in this year’s Indianapolis 500, crashed into Philippe coming out of a blind corner at Infineon Raceway. He was scheduled for an MRI exam later Saturday, but IndyCar officials didn’t expect any further updates on his status until today.

Power, Penske’s third driver, was airlifted to nearby Santa Rosa Memorial Hospital. Philippe was taken by ambulance to the same hospital, where he was undergoing surgery on his foot.

IndyCar officials said both drivers were reported to be awake and alert and were to be hospitalized at least overnight. They each withdrew from the race, meaning no new driver will fill the seat.

Philippe lost control at the top of the hill on Turn 3A, and the front end of his car was initially clipped by E.J. Viso. Power arrived moments later and couldn’t avoid an ugly crash, T-boning Philippe’s car.

“It’s pretty serious,” said Power’s Penske teammate Ryan Briscoe, who qualified second Saturday. “We definitely need to look at the safety over here and what can be done differently with spotting or whatever to Turn 3A.”