Top Gear's Richard Hammond is seriously ill in hospital after a crash in a rocket-powered car while filming for the programme.
The 36-year-old presenter was taken by air ambulance to Leeds General Infirmary's neurological unit.
A spokesman for the hospital said Mr Hammond was "stable".
Mr Hammond had been driving a dragster-style car capable of reaching 300mph at the former RAF airfield in Elvington,
Former firefighter Dave Ogden, who runs private firm Event Fire Services, was one of the first people at the scene of the crash.
He said: "We were down there with Top Gear who were filming him trying to break the British land speed record.
"On the previous run, the car had just gone over 300mph but I am not sure if it had broken the record.
"They had just done one more run and were planning to finish when it veered off to the right.
"One of the parachutes had deployed but it went on to the grass and spun over and over before coming to a rest about 100 yards from us."
He said his crew and an ambulance that was already on the airfield rushed over and found the car upside down and "dug in" to the grass.
Mr Ogden said he felt for a pulse and heard Mr Hammond breathing before the emergency crews worked together to turn the car the right way up and then cut him free.
He added: "He was regaining consciousness at that point and said he had some lower back pain. But he was drifting in and out of consciousness a little bit."
Former Top Gear presenter Quentin Willson said the presenter was "irreplaceable".
He said: "He is a wonderful, unique and distinctive Top Gear presenter.
"He has brought an awful lot to the programme and his indefatigable energy, the fact that he tries absolutely anything once, may have been the reason that he has overstepped the mark a bit.
"He has turned Top Gear into a gang show with Jeremy and James and the three of them have wowed audiences all over the world and he is an international personality."
Mr Wilson added: "There is no pressure from the BBC or the producer to take undue risks.
"But that pressure is in your own head. You want to do an item on the programme which is mindblowing.
"You want to do a fantastic item that blows everybody away."
The presenter, who works on Top Gear with fellow presenters Jeremy Clarkson and James May, was born in
In addition to presenting Top Gear for the BBC, he also fronted Brainiac on Sky One until recently.