Two cameramen were taken to hospital after falling from an elevated platform before racing at Hamilton.
A delay to racing was initially announced while emergency services attended to the injured men, with the meeting eventually called off just after 3.35pm.
The cameraman were working for RaceTech, who provide broadcast services for racing, and an investigation is already underway.
A statement from the company read: “Following a serious incident prior to the first race at Hamilton Park involving a mobile elevated camera platform, two freelance camera operators, Robbie Cotgrave and Kit Campbell, have been seriously injured and taken to hospital.
“A full investigation is underway into the cause of the incident.
“Our thoughts and concerns are very much with our two colleagues at this time.”
Clerk of the course Harriet Graham said the well being of the cameramen soon became the priority over the need to stage the fixture.
She said: “About half an hour before the first race an incident happened involving RaceTech operators and a hoist.
“Our emergency teams reacted immediately and then we needed to call the fire service and ambulances, so we had fire engines on site and the police.
“It took them a long time to assess the situation and extract them and take them off to hospital. During this time the timeline became more and more extended.
“The decision was we would wait for CID to arrive to see if we could continue racing, but they indicated they wouldn’t be making a decision in the short term.
“So, we held a stewards’ inquiry and the decision was made to call off racing.
“Whilst that is a big decision, we felt we had no timeline for when we could start racing and the main thing is all our thoughts are with the two guys who have gone off to hospital for further assessment. Let’s hope they are OK.
“In the bigger picture racing is secondary in this situation. A nasty accident has happened, two people are injured. They are having the best care they could have and received immediate attention.”
A Scottish Fire and Rescue Service spokeswoman said: “We were alerted at 1.35pm on Tuesday, June 29 to an incident at Hamilton Park Racecourse, Hamilton.
“Operations Control mobilised two appliances to the scene and using an aerial rescue pump firefighters rescued two male casualties who had fallen onto the roof of a vehicle before handing them into the care of the Scottish Ambulance Service.
“Crews left the scene after ensuring the area was made safe and there were no further reported casualties.”
The Scottish Ambulance Service added: “We received a call at 13.38hrs this afternoon to attend an incident at Hamilton racecourse. Two ambulances and two rapid response vehicles were dispatched to the scene.”
A spokesperson for British Horseracing Authority said: “Everybody at the BHA is concerned by the reports from Hamilton this afternoon and our thoughts are with the two RaceTech employees who have been injured.
“We wish both a full and speedy recovery.”