Twelve horses have been killed in a road accident in Canada.

The horses died when a trailer carrying 44 animals overturned on a motorway in Calgary, Alberta last Friday, 24 October.

The vehicle was heading to Fort Macleod, where some of the horses would go to slaughter and others to new owners.

It took 3 hours to free the horses. Fireman, passers-by and staff from the nearby Spruce Meadows — a major Canadian show jumping facility — all helped to free the trapped horses and round up the survivors.

Most of the 44 horses walked out on their own, but 12 were dead and several others were injured and had to be pulled out with ropes.

Firecrews removed the rear of the truck with a plasma cutter while saws were used to gain access via the roof of the trailer.

The Canadian Press reported that the driver lost control of the vehicle and is now facing several charges.

According to The Winnipeg Free Press he has been charged with careless driving, failing to produce insurance, driving with no license plate on the trailer, failing to notify registry of change of address and operating a vehicle with the wrong class of license.

The surviving horses are currently recovering at pasture.