Italian rider Marco Simoncelli has died after a horrific crash at the Malaysian MotoGP in Sepang.
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.
The 24-year-old had his helmet knocked off and was hit by both other riders.
American rider Edwards also fell but escaped serious injury - while 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.
At first, officials were looking to restart the race before the extent of Simoncelli's injuries became clear.
Honda rider Simoncelli first entered MotoGP for the 2010 season and won his first pole position at the Catalunya race in June this year.
SIMONCELLI FACTFILE
- Born: 20 January 1987, Cattolica, Italy
- 125 Championship: 2002-05, 2 wins
- 250 Championship: 2006-09, 12 wins
- MotoGP: 2010-11
Simoncelli's first podium finish came in the Czech Republic in August when he finished third but he bettered that with a second-place finish at the Australian GP.
World champion Casey Stoner said: "As soon as I saw the footage it just makes you sick inside. Whenever the helmet comes off that's not a good sign."
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.
Simoncelli dies after horrific crash
Marco Simoncelli was killed after being involved in a horrific crash in the MotoGP race at Sepang, Malaysia.Both riders appeared to hit Simoncelli, whose helmet came off during the incident.
The race was red flagged immediately, and cancelled a few minutes later when it emerged that Simoncelli was in a critical condition. He died soon afterwards.
Honda rider Simoncelli was in his second season in MotoGP, and established himself as a fan favourite with his flamboyant riding style.
He took his maiden podium spot in the series in the Czech Republic two months ago, and followed that up with a second place finish at the recent Australian Grand Prix.
Simoncelli's death is the second casualty in the top level of motorsport, coming just a week after British driver Dan Wheldon was killed in an IndyCar race in Las Vegas.
Another tragedy rocks motorsport after Simoncelli is killed in MotoGP crash
Last updated at 4:23 PM on 23rd October 2011
- WARNING: INCLUDES GRAPHIC PICTURE CONTENT...
Motorsport was mourning its second death in the space of a week after Italian Marco Simoncelli was killed in a crash at the Malaysian Moto GP.
The Gresini Honda rider lost control of his bike on the second lap of the circuit in Sepang and appeared to be hit by Colin Edwards and then Valentino Rossi as he slid across the track.
Agony: Marco Simoncelli's father is comforted as he waits outside a medical centre where the rider was taken following a crash at the Malaysian Grand Prix
The 24-year-old's helmet came off in the collision and he was taken to the medical centre for treatment, but died from his injuries.
Moment of horror: Simocelli loses control on the second lap before fatally colliding with Colin Edwards as Valentino Rossi ahead manages to escape
Simoncelli's death comes exactly a week after British racing driver Dan Wheldon, a former IndyCar champion and two-time Indy 500 race winner, was killed in a 15-car pile-up at the Las Vegas Motor Speedway. The Buckinghamshire driver was 33.
The organisers cancelled Sunday's race as soon as the extent of Simoncelli's injuries became apparent.
Tragedy: Race marshalls attend to Honda rider Simoncelli (C) following his fatal crash just four minutes after the start of the Malaysian MotoGP race
Speaking at a press conference following the tragedy, medical director Dr Michele Macchiagodena said of Simoncelli:
'Because of the crash he had during the race, in which he was hit by other riders, he suffered a very serious trauma to the head, to the neck and the chest.
'Because of the crash he had during the race, in which he was hit by other riders, he suffered a very serious trauma to the head, to the neck and the chest.
'When our medical staff got to him he was unconscious. In the ambulance because there was a cardiac arrest they started CPR (cardiac pulmonary resuscitation).
'Immediately in the medical centre, with the help also of the doctor of our staff at the Clinica Mobile and local doctors, he was intubated and it was possible to take off some blood from the thorax.
'The CPR was continued for 45 minutes because we tried to help him for as long as we thought it was possible. Unfortunately it was not possible to help him and at 16:56 (local time) we had to declare he was dead.'
Moment of horror: Simoncelli loses control on the second lap
Collision: Simoncelli fatally falls off of his Honda after colliding into Colin Edwards
Fall: Edwards spins off the track along with Simoncelli's bike as the 24-year-old Italian devastatingly lies motionless
A statement on the MotoGP official website read: 'On Sunday 23rd October, during the MotoGP race at the Shell Advance Malaysian Motorcycle Grand Prix at the Sepang International Circuit, San Carlo Honda Gresini's Italian rider Marco Simoncelli suffered a serious accident in which he received critical injuries.
'The race was stopped immediately with the red flag and Simoncelli was transported by ambulance to the circuit medical centre where the medical staff worked to resuscitate him.
'Despite their efforts, Marco sadly succumbed to his injuries at 4:56pm local time.
'Everybody involved in MotoGP extends its deepest condolences to Marco's family, friends and team at this tragic loss.'
Sorrow: Honda team members (above and below) react to the sad news
Spanish rider Dani Pedrosa had a dispute with fellow factory Honda rider Simoncelli earlier this season, but news of his rival's death left last season's championship runner-up reeling.
Repsol Honda's Pedrosa said: 'In a tragedy like this there is not much to say. I just want to give my condolences to his family and all the people who love him. I've been with his father and all we could do was to hug, nothing else matters.
'It was a fatal accident and everybody in the paddock remains in shock.
'Many times we ourselves forget how dangerous this sport can be and when you lose people on the way nothing has any meaning. It's clear that we all do what we like, what we love, but on days like today nothing matters.'
Losing control: Simoncelli (No 58) crashed on the second lap of the race, riding between Edwards and Valentino Rossi
Emergency: Race marshalls quickly arrive at the scene to assist the stricken Simoncelli
Simoncelli, who won the 250cc world championship in 2008, clinching the crown in Sepang, stepped up to MotoGP in 2010.
His death was the first fatality in MotoGP since Japan's Daijiro Katoh died from his injuries sustained at the 2003 Japanese Grand Prix.
When asked about Simoncelli's helmet coming off, race director Paul Butler said at the press conference: 'I think if I may reply, that will be for another occasion. Quite clearly the consequences and circumstances surrounding the accident will be thoroughly investigated.'
Wheeled away: Track officials remove Simoncelli's motorcycle after the dreadful accident
Newly-crowned champion Casey Stoner admitted immediately after the crash he had feared for Simoncelli.
'As soon as I saw the footage it just makes you sick inside,' the Australian told BBC2.
Cancelled: Rubbish covers the track after the race was abandoned early in Sepang
'Whenever the helmet comes off that's not a good sign.'
Tributes poured in for Simoncelli from teams and riders.
Briton's Jenson Button wrote on his Twitter account: 'R.I.P Marco... Such an exciting talent lost. My thoughts are with his family, friends and everyone involved in MotoGP. Motorsport can be so cruel...'
British MotoGP rider Cal Crutchlow wrote on Twitter: 'RIP Marco Simoncelli! A great rider and all round nice guy. My thoughts are with all his family & friends. I will never forget today.'
Delivering the news: MotoGp officials relay the tragic announcement
Formula One driver Mark Webber tweeted: 'R.I.P Marco A special talent that will be missed... Thinking of your loved ones, and all the motogp paddock..mark.'
A message on Simoncelli's Gresini Honda team website read simply 'CIAO "SUPER SIC"'.
Support: Simoncelli girlfriend Kate is consoled by a TV crew member following her partner's tragic crash
Paolo Simoncelli, Marco's father, is comforted by his son's manager Carlo Pernat outside the medical center following the accident
The Rizla Suzuki team wrote: 'All at Rizla Suzuki are deeply affected by today's tragic events and send their deepest condolences to Marco's family and friends during this time of great loss.
'R.I.P Marco Simoncelli, 20 January 1987 - 23 October 2011 - A true competitor.'
MARCO SIMONCELLI: 1987 - 2011
1987: Born in Cattolica, Italy on January 20.
1996: Runner-up in the Italian Minimoto Championship.
1999: Champion of the Italian Minimoto Championship.
2000: Claims a back-to-back title in the Italian Minimoto Championship and is runner-up in the European Minimoto Championship.
2001: Moves up to the the Italian 125cc Championship and wins the title in his rookie year.
2002: Wins the European 125cc title.
2003: Takes part in his first full season in the 125cc World Championship with the Matteoni Racing team.
2004: Joins the Rauch Bravo team and wins his first Grand Prix at a rain-soaked Jerez.
2005: Completes another 125cc campaign with the Nocable.it Race team and finishes fifth in the final standings.
2006: Moves up to the 250cc class riding for Gilera. Finishes the season in 10th overall with a sixth place finish at the Chinese Grand Prix his best result.
1996: Runner-up in the Italian Minimoto Championship.
1999: Champion of the Italian Minimoto Championship.
2000: Claims a back-to-back title in the Italian Minimoto Championship and is runner-up in the European Minimoto Championship.
2001: Moves up to the the Italian 125cc Championship and wins the title in his rookie year.
2002: Wins the European 125cc title.
2003: Takes part in his first full season in the 125cc World Championship with the Matteoni Racing team.
2004: Joins the Rauch Bravo team and wins his first Grand Prix at a rain-soaked Jerez.
2005: Completes another 125cc campaign with the Nocable.it Race team and finishes fifth in the final standings.
2006: Moves up to the 250cc class riding for Gilera. Finishes the season in 10th overall with a sixth place finish at the Chinese Grand Prix his best result.
2008: June - Wins his first 250cc race at the Italian GP in Mugello in controversial circumstances when Hector Barbera crashed into him after Simoncelli appeared to try to block him off.
October - Wins the 250cc World Championship after a successful season with Gilera with a third place finish in the Malaysian Grand Prix at Sepang.
2009: Finishes third overall in the 250cc World Championship behind Japan's Hiroshi Aoyama and Spain's Barbera.
2010: Moves up to ride in his debut MotoGP season for Honda. Finishes 16 of the 18 races en route to eighth place in the championship.
2011: May - Collides with Dani Pedrosa while battling for second in the French GP. The resulting crash saw Pedrosa break his collarbone and Simoncelli receive a ride-through penalty, eventually finishing fifth. Simoncelli accepted he needed to re-evaluate his driving style and at times be more cautious.
June - Claims his first MotoGP pole at the Catalan GP but a poor start resulted in a sixth placed finish.
October 23 - Killed in a crash during the Malaysian GP in Sepang.
October - Wins the 250cc World Championship after a successful season with Gilera with a third place finish in the Malaysian Grand Prix at Sepang.
2009: Finishes third overall in the 250cc World Championship behind Japan's Hiroshi Aoyama and Spain's Barbera.
2010: Moves up to ride in his debut MotoGP season for Honda. Finishes 16 of the 18 races en route to eighth place in the championship.
2011: May - Collides with Dani Pedrosa while battling for second in the French GP. The resulting crash saw Pedrosa break his collarbone and Simoncelli receive a ride-through penalty, eventually finishing fifth. Simoncelli accepted he needed to re-evaluate his driving style and at times be more cautious.
June - Claims his first MotoGP pole at the Catalan GP but a poor start resulted in a sixth placed finish.
October 23 - Killed in a crash during the Malaysian GP in Sepang.
Italian rider Marco Simoncelli has died after a horrific crash at the Malaysian MotoGP in Sepang.
By : BBC News
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.
The death is the first fatality in MotoGP since Japan's Daijiro Katoh died from injuries sustained at the 2003 Japanese GP while, last year, Japan's Shoya Tomizawa died in a similar crash to Simoncelli in aMoto2 race in San Marino.
Simoncelli's death comes a week after British IndyCar driver Dan Wheldon was killed in Las Vegas following a 15-car crash.
ANALYSIS
Matt RobertsBBC MotoGP presenterRead Steve Parrish's tributeMarco was flamboyant on and off the track. When someone dies, everyone always says they loved life. But he had a very vibrant personality. He already had a huge fanbase around the world, partly down to aggressive riding - but also because he was just a cool guy. He didn't take himself too seriously and would have been a big star for next year.
BBC MotoGP presenter Matt Roberts said: "Marco lost his helmet in the crash. The officials said that, when the track medics got to him, he was in cardiac arrest. They tried to resuscitate him in the ambulance and the medical centre.
"Both riders collided with him and the impact corresponded to him losing his helmet. The saddest thing is that Valentino [Rossi] and Marco were very close friends.
"Colin [Edwards] has a dislocated shoulder and is in a lot of pain. He and Valentino are absolutely devastated."
A MotoGP statement read: "On Sunday, 23 October, during the MotoGP race at the Sepang International Circuit, San Carlo Honda Gresini's Italian rider Marco Simoncelli suffered a serious accident wherein he sustained critical injuries.
"The race was stopped immediately with the red flag and Simoncelli was transported by ambulance to the circuit medical centre where the medical staff worked to resuscitate him.
"Despite their efforts, Marco sadly succumbed to his injuries at 4.56pm local time [0956 BST].
"Everybody involved in MotoGP extends its deepest condolences to Marco's family, friends and team at this tragic loss."
And Sepang circuit chairman Mokhzani Mahathir added: "This is a one-of-a-kind freak incident where the helmet came off and I am sure FIM [International Federation of Motorcycling] and MotoGP will be looking into this."
Honda rider Simoncelli entered MotoGP for the 2010 season and won his first pole position at the Catalunya race in June this year.
Simoncelli's first podium finish came in the Czech Republic in August when he finished third but he bettered that with a second-place finish at the Australian GP.
World champion Casey Stoner said: "As soon as I saw the footage it just makes you sick inside. Whenever the helmet comes off that's not a good sign."
British MotoGP rider Cal Crutchlow tweeted: "RIP Marco Simoncelli! A great rider and all round nice guy. My thoughts are with all his family & friends. I will never forget today."
Australian Formula 1 driver Mark Webber tweeted: "RIP Marco. A special talent that will be missed. Thinking of your loved ones and all the MotoGP paddock."
Major Italian sports events on Sunday observed a minute's silence in memory of Simoncelli, who was a big fan of football club AC Milan.
In their Serie A fixture against Lecce, Milan wore black armbands and came back from three goals behind to win 4-3.
