Racing was stopped when stepping on the fourth minute when Simoncelli fell in the middle of the track and was hit by Colin Edwards and Valentino Rossi as his body slid on the asphalt.
The helmets worn 24-year-old drivers to race off and supervisory officers were flying the red flag stopped the race mark.
Simoncelli was raised to the ambulance to the circuit medical center, but at 16:56 local time, he was rumored last breath because it hurt too badly, as reported by Autosport.com.
Year is arguably the best year Simoncelli, who just last year stepped MotoGP level.
Honda engineering excellence helped him shine compete with Repsol Honda team. He successfully won his first pole position in the Catalonia Grand Prix in June this year.
Colin Edwards also dropped due to the accident, but less seriously injured, while Rossi and Ducati steed can go back and into the pit.
"Once I saw the video footage makes me nauseous. Helmets are not a good sign regardless, "he said, quoted from BBC Sports.
Medical Director Marco Simoncelli Explains Cause of Death
Medical team finally launch his cause of death Marco Simoncelli. Medical Director Dr. Michele Macchiagodena call, Simoncelli died from injuries in the head, neck, and chest.
"I am very sad to be here to tell you about the death of Marco Simoncelli due to severe accidents caused by other drivers, there is trauma to the head, neck and chest," said Macchiagodena a news conference at the Sepang Circuit on Sunday (10/23/2011).
"When our team arrived, he was unconscious. When the ambulance arrived, he was immediately given CPR and also received other standard treatments. CPR was continued for 45 minutes because it can help her. Unfortunately it can not be helped. He died at 16:56 (local time, ed), "he continued.
The press conference lasted for six minutes and was also attended by Javier Alonso (Dorna Events Managing Director), Franco Uncini (Safety Delegates), Claude Danis (Presidential Commission on Safety), and Paul Butler (Race Director).
As reported earlier, the accident occurred when the motor Simoncelli slip sideways when cornering in the middle of the second lap.
Unfortunately for Simoncelli, he fell in the middle of the track. Impact, he was hit by Colin Edwards and Valentino Rossi who was driving behind him. Red flags were hoisted and the race was stopped.