Champion jockey Jim Crowley and fellow rider Freddy Tylicki have been taken to hospital after four horses fell in a race at Kempton.
An air ambulance was called and the meeting was later abandoned after the incident in the 15:20 GMT race.
Crowley, 38, was taken by ambulance and Tylicki, 30, was flown to the major trauma unit at St George’s Hospital in Tooting with suspected spinal injuries.
The horses were not reported to be seriously injured.
Jockeys Steve Drowne and Ted Durcan were also thrown from their mounts on the turn into the home straight but walked back to the weighing room.
Crowley was crowned British flat racing’s champion jockey for the first time on 15 October.
The incident happened in the third race, the maiden fillies’ stakes, as the field rounded the home turn in and Tylicki suffered a heavy fall on Nellie Dean after appearing to clip heels with leader and eventual winner Madame Butterfly.
Crowley and Electrify were racing immediately behind and were brought down, as was Drowne’s mount Skara Mae. Durcan was also caught up in the melee and was unseated from Sovrano Dolce.
Following a delay of more than an hour, the decision was taken to abandon the rest of the meeting after consultation with jockeys at the track.
Kempton clerk of the course Barney Clifford told Racing UK: “Having discussed it with jockeys and the stewards, the unanimous decision as a mark of respect for the two lads that have been injured, Jim and Freddy, was that we abandoned racing.
“You don’t expect those things to happen on the Flat. I just hope and pray that Freddy and Jim are OK.
“Both were on spinal boards and both gave their consent to me and the doctor to update their next of kin family members. I can’t say anymore than that at this stage.”
Article source: http://www.bbc.co.uk/sport/horse-racing/37828149