US Moto GP, Laguna Seca
Date: 4-5 July
Sunday 5 July: 2200-2300, BBC Two/online
Title hopefuls crash in MotoGP qualifying
Jorge Lorenzo earned pole position for the US MotoGP but the Spaniard also suffered a heavy fall, as did third-fastest rider Casey Stoner.
The pair needed medical attention after they both had huge high-side crashes and Lorenzo will need further checks to determine whether he can race.
World champion Valentino Rossi remained upright throughout, and pinched second place on the grid with his last lap.
Britain's James Toseland also suffered a crash and came in a lowly 15th.
Lorenzo had already fallen from his Yamaha once in the session, and jogged back to the garage to switch bikes, before he came off spectacularly as qualifying drew to a close.
He landed on his right shoulder on the track and then slid headfirst about 30 metres in the sand.
The 22-year-old was taken off the track by ambulance and it was not immediately clear how badly he was injured.
He will have a late medical check just hours before the race begins but is optimistic about his chances of racing.
"We were really comfortable and competitive on this track, but when I had my last chance to do a quick lap time I found some slower riders on track and they wanted to follow me," said Lorenzo.
"I decided to slow down for a while because I wanted to be alone but the rear tyre was too cold for the speed I was doing. I went into the corner and I crashed.
"I'm disappointed for these two crashes but I am okay and I am optimistic that I will be able to ride on Sunday."
Stoner, who started from the pole last year at Laguna Seca, flipped off his bike moments after Lorenzo's crash and also landed on the track.
He was driven back to his team's garage and could be seen limping as he got off a cart.
Rossi wished a speedy recovery to both Lorenzo and Stoner.
"I just hope that Casey and Jorge are fit and are able to race, because for sure it would be a great battle between us, as our pace on race tyres is very similar," said Rossi.
United States MotoGP qualifying result:
1. Jorge Lorenzo (Spain) Yamaha 1 minute 21.678 seconds
2. Valentino Rossi (Italy) Yamaha 1:21.845
3. Casey Stoner (Australia) Ducati 1:21.910
4. Dani Pedrosa (Spain) Honda 1:22.113
5. Andrea Dovizioso (Italy) Honda 1:22.135
6. Toni Elias (Spain) Honda 1:22.146
7. Colin Edwards (U.S.) Yamaha 1:22.490
8. Nicky Hayden (U.S.) Ducati 1:22.540
9. Chris Vermeulen (Australia) Suzuki 1:22.633
10. Loris Capirossi (Italy) Suzuki 1:22.662