Racing's return at Newcastle was marred by a fatal injury to one of the runners in the feature race.
December Second fell in the closing stages of the Betway Handicap and brought down outsider Financial Conduct.
The incident happened with a quarter of a mile left to run.
Vets were quickly on the scene, but sadly Phil Kirby's dual bumper winner could not be saved.
"Jim Crowley and PJ McDonald are both thankfully OK after taking falls in that previous race," said on-course Sky Sports Racing presenter Simon Mapletoft.
"Now the stricken horse was December Second.
"Trainer Phil Kirby felt that he probably clipped heels and of course the screens were very quickly up.
"He was attended immediately by the veterinary officers but I am afraid to say that they haven't been able to save December Second, so my commiserations go to all connected with Phil Kirby's stable and with that horse who of course was a very promising individual.
"It's not nice for any stable to suffer the loss of any horse, never mind one who could have been a real flagship."
December Second was making his debut on the all-weather on his seasonal return, the son of Teofilo's first start since winning on at Haydock in August.
As racing fans left their tributes on social media, Kirby tweeted: "A beautiful horse with a big future.
"We're so sad to have lost December Second this afternoon, it certainly doesn't get any easier.
"Our thought with the whole team and his owner #RestInPeace."
The riders involved, PJ McDonald and Jim Crowley, were brought back to the weighing room.
Newcastle's ninth race was delayed by over ten minutes.
Crowley was replaced by Oisin Murphy on the runner-up Thibaan.
A spokesperson for Newcastle Racecourse said: "Everyone at Newcastle Racecourse sends their condolences to @PKirbyRacing after December Second was fatally injured in the Betway Handicap."
