Former Formula One world champion Lewis Hamilton crashed at more than 250 kilometres per hour during Saturday's first qualifying session for the German Grand Prix.
The Briton climbed out of his car shaken and winded but with no apparent serious injury. The impact came after the Mercedes driver's brakes failed on entry to the hairpin leading into the stadium section of the Hockenheimring circuit.
Hamilton was able to tell the team he was okay by radio and was driven to the race medical centre for an examination.
"I hit something," Hamilton told the team. "I hit... hit the brakes - the brakes failed."
The session was red flagged to a halt for repairs to the barriers, notably a wall of tyres into which Hamilton's car plunged on impact as he lost control. The front of his car suffered most damage.
Hamilton will take no further part in the qualifying session and will start Sunday's race from the back of the grid.
For Hamilton, it was a major setback after he had managed to reduce Mercedes team-mate and championship leader Nico Rosberg's lead to just four points with a victory in the British Grand Prix where the German retired.
It is the first time Hamilton has failed to proceed to the third part of qualifying, the top ten shootout, since the 2010 Malaysian Grand Prix.
His Mercedes team confirmed he had told them he suffered a brakes failure, but said they had to make further investigations to discover the cause of the accident.
Hamilton was taken to the circuit medical centre where he was examined carefully and joined by his personal fitness trainer and physiotherapist.
It was reported that they were concerned about his knees.
His car hit the barriers heavily after, it appeared, the wheels locked up starting with the front left wheel and then the rear wheels.
Television pundits and former racing drivers including Britons Martin Brundle, 2006 world champion Damon Hill and Johnny Herbert told Sky television they believed the car's right front brake had failed, causing the spin.
"There was clearly something wrong with the car," said Hill.
"It is not just about his ego, but about the car. This is going to make it so much harder for him in the championship."
Hamilton was aware of the car's failure to brake and removed his hands from the steering just before impact.
The team confirmed that Hamilton's car had suffered a front right brake disc failure.
Having won his home British event at Silverstone two weeks ago, Hamilton has 161 points to Rosberg's 165.