Top gear presenter Richard Hammond suffered a "significant brain injury" after the 370mph jet-powered car he was driving crashed on an airfield, doctors said last night.
The 36-year-old is in a serious but stable condition at Leeds General Infirmary where friends and family are keeping a bedside vigil following Wednesday's accident at Elvington airfield near York.
His father expressed fears about the injuries he received when the record-breaking Vampire dragster veered off the runway, flipped over several times and crashed onto grass.
Alan Hammond, who is looking after his son's daughters Willow, two, and Isabella, five, in Gloucestershire, said the family was unsure if the presenter would live or die.
But Richard's brother, speaking to reporters at the hospital in Leeds, was more upbeat. He said: "He's making a bit of good progress."
Doctors at the hospital said the brain injury gave them "cause for concern" but added that they were "reasonably optimistic" he would make a good recovery.
Top Gear's Jeremy Clarkson paid tribute to Hammond as he visited him with co-presenter James May.
He said: "I would just like to say how heartened Richard will be when I tell him just how many motorists and truck drivers on my way here wound down their windows to say they were rooting for him.
"Both James and I are looking forward to getting our `Hamster' back."
Police and safety experts have launched an investigation into the crash, which happened after Hammond had been driving at speeds close to 300mph as part of filming for the show.
Organisers, who have denied reports that Hammond was trying to break the British land speed record, said the "highest" safety standards had been followed.