video not for the faint hearted.
The race was stopped after four minutes 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.
He was taken by ambulance to the circuit’s medical centre, but at 16:56 it was announced he had succumbed to his injuries.
The Italian started in the 125cc class in 2002 and moved up to the 250cc class in 2006.
He claimed the 250cc world title in 2008.