A stables worker has died after being injured at Kempton Park racecourse.
It is thought the groom, who has been named by his employer as Ken Dooley, was kicked by a horse.
Surrey Police said it had been reported a man in his 50s sustained a serious injury to the head while tending to a horse in the stables.
Mr Dooley had worked at the West Sussex yard of horse trainer Amanda Perrett, who said he had been with the close-knit family business for seven years.
In a statement, Ms Perrett said: “It is with huge sadness that I can confirm we lost our friend and colleague Ken Dooley after an incident in the stable yard at Kempton last night.
“He was an excellent employee, very experienced with racehorses having worked all of his life with them as a jockey, trainer and jockey coach around the world.”
Police were called to the Sunbury-on-Thames venue at 21:20 BST, and doctors at the course also attended.
Saturday’s fixture was abandoned with two races remaining as emergency teams responded to the accident.
A police spokeswoman confirmed the death was not being treated as suspicious and also said the man’s family had been informed.
She said police would be working with the coroner and local authority to establish the circumstances surrounding Mr Dooley’s death.
Jockey Martin Dwyer, who was riding at the course, told Racing UK there was a “sombre mood” and shock as the news emerged.
He said: “Unfortunately, horses do kick out and I believe that’s what happened.
“They have metal shoes on and if you get a kick from a horse it can be very serious.”
Staff as well as jockeys at Chepstow and Goodwood are wearing black armbands on Sunday as a mark of respect.
In a statement, the Racecourse Association said: “Racecourses do everything they can to provide a safe working environment in all areas and are equipped to provide the highest level of medical care and attention whenever it is required.
“This tragic accident is a reminder of the dangerous nature of the work stable staff do day in day out, and our thoughts are very much with everybody affected.”
Chief executive of the British Horseracing Authority Nick Rust said: “The entire industry will join in mourning over this tragedy.
“We owe so much in our sport to the racing grooms who provide such first-class care and attention to our horses.
“The love and attention that they give to their mounts is unconditional and comes with that small but ever-present level of risk that exists when working with large animals.”
Organisers at Kempton Park – one of the UK’s best known racecourses – announced Saturday’s cancellation on social media.
Steve Parlett, general manager at the racecourse, said: “All the team here are shocked and upset by the sad loss of a training stables employee last night.
“Our thoughts and deepest condolences are very much with his family, friends and colleagues.”
More From this publisher : HERE