IndyCar medical staff have confirmed that Dario Franchitti sustained concussion and two fractures in his frightening final-lap crash during Sunday's IndyCar race in Houston.
Franchitti was launched airborne and into the catch fencing when he caught the rear of an out-of-shape Takuma Sato.
His Ganassi car rolled briefly along the barrier before bouncing back into the middle of the track.
The Scot remained in the car until he was extracted by medical crews, and was taken directly to the nearby Memorial Hermann Texas Medical Centre, where he was assessed and found to have suffered a concussion, a fractured vertebra that will not require surgery, and a fractured right ankle.
He will be kept in hospital overnight.
Meanwhile, race organisers have confirmed that 14 spectators were injured when a piece of catch fencing that was torn loose during Franchitti's accident landed in a nearby grandstand.
"Following an accident that occurred on-track at the Grand Prix of Houston this afternoon our greatest concern is for our fans and participants," read a joint statement from race promoter Mi-Jack Promotions, Reliant Park, and IndyCar.
"An IndyCar official and IndyCar driver, Dario Franchitti, along with two fans were transferred to an area hospital for evaluation. Eleven fans were additionally evaluated on site.
"Officials are investigating the incident and currently do not have further information at this time. Fan and driver safety are always a primary concern and we will provide further details as they are available."