Marco Simoncelli is killed in MotoGP crash in Malaysia. His death comes one week after Indianapolis 500 winner Dan Wheldon was killed at Las Vegas Motor Speedway.
The race was stopped on lap two when Simoncelli's bike veered across the track at turn 11 into the path of Colin Edwards and Valentino Rossi.
The 24-year-old had his helmet knocked off and was hit by both other riders.
American rider Edwards also fell and dislocated his shoulder - while Simoncelli's fellow Italian Rossi was able to return to the pits.
Simoncelli lay motionless on the track after the impact, while the race was immediately red-flagged.
Medical director Michele Macchiagodena said Simoncelli suffered a "very serious trauma to the head, to the neck and the chest".
At first officials were looking to restart the race before the extent of Simoncelli's injuries became clear.
The race was cancelled amid confusion in the grandstand, with fans throwing bottles to show their initial displeasure.
Simoncelli's death comes a week after British IndyCar driver Dan Wheldon was killed in Las Vegas following a 15-car crash.
