A kart racing driver was killed when he was thrown from his vehicle as it hit a crash barrier at the Silverstone race track in Northamptonshire.
The man was thrown clear of the kart in the accident during the final round of the 2006 British Superkart Championships on Sunday afternoon.
He was then hit by a chasing kart at the entrance to the Luffield hairpin.
The man, who was in his 50s and described as a very experienced driver, has not yet been named.
'Shocked'
Ian Rushforth, the series co-ordinator of the British Superkarts Association, said the driver had been racing in the fastest class.
He said other drivers had been left shocked by the accident but the sport itself had an excellent safety record.
"Within the Superkart fraternity there are about 150 of us and we see the guys week in and week out. It is almost family," he said.
"Because we are a tight-knit family we always feel it."
Northamptonshire Police traffic officers are investigating the crash.
The two metre-long 250cc karts are capable of speeds up to 150mph.
Drivers sit low down in the cramped compartments, but are not strapped in by seatbelts.