disposed in the portion of the exhaust passage through which exhaust gas is applied to the turbine of the secondary turbosupercharger to be closed so as to supply the turbine of the primary turbosupercharger with the exhaust gas collectively when the exhaust gas flow in the exhaust passage is relatively small and to be opened so as to supply both the turbines of the primary and secondary turbo-superchargers with the exhaust gas when the exhaust gas flow in the exhaust passage is relatively large. With such an operation of the exhaust cutoff valve, intake air compressed by the blower of the primary turbosupercharger or the blowers of the primary and secondary turbosuperchargers is supplied to a combustion chamber of the engine with required intake air mass flow respondingMONTREAL, QUE.: JUNE 9, 2013 -- Red Bull F1 driver Sebastian Vettel of Germany kisses his trophy as he celebrates after finishing first in the Formula One Canadian Grand Prix at the Circuit Gilles Villeneuve in Montreal on Sunday, June 9, 2013. (Dario Ayala / THE GAZETTE)

MONTREAL — François Dumontier had every reason to be glowing at 5 p.m. Sunday, another crowd-pleasing Formula One race in the books.

But the president of the Canadian Grand Prix was about the colour of his crisp white shirt, clearly devastated when he met a hastily gathered group of reporters in a press conference room not far from the start/finish line of Circuit Gilles Villeneuve.

With Dr. Jacques Bouchard, chief medical officer of the race, Dumontier bore news of a terrible accident that, an