Swiss Moto3 rider Jason Dupasquier has died aged 19 from injuries sustained in a crash in qualifying at the Italian Grand Prix, organisers MotoGP announced on Sunday.
"We're deeply saddened to report the loss of Jason Dupasquier," MotoGP said on Twitter.
"On behalf of the entire MotoGP family, we send our love to his team, his family and loved ones. You will be sorely missed, Jason. Ride in peace," the statement added.
The Careggi hospital in Florence treating Dupasquier confirmed that the teenager had suffered brain injuries "incompatible with life" in the multi-bike accident at Mugello on Saturday.
Dupasquier, in his second season in Moto3, fell and was struck by at least one bike, before sliding along the track, during qualifying.
Doctors rushed to the scene and after attending to him for 40 minutes on the circuit had him airlifted to hospital.
He underwent chest surgery overnight "for a vascular lesion" and had suffered "severe brain damage", a hospital spokesman told AFP earlier on Sunday.
Motorcycling's governing body the FIM, the team's IRTA umbrella association, and the sport's commercial rights holder DORNA issued a joint statement on the tragic news.
"Following a serious incident in the Moto3 Qualifying 2 session at the Gran Premio d'Italia, it is with great sadness that we report the passing of Moto3 rider Jason Dupasquier," it read.
It said after Dupasquier's crash medical officers "arrived at the site immediately and the Swiss rider was attended to on track" before his transfer to hospital.
"Despite the best efforts of circuit medical staff and all those subsequently attending to the Swiss rider, the hospital has announced that Dupasquier has sadly succumbed to his injuries," the statement continued.
His team, Pruestel GP, had already pulled out of Sunday's race, posting on Facebook: "PruestalGP decided not to race today in the #italianGP. The situation of @jasondupasquier50 is still critical and all our thoughts are with him."
