Three tragedies have occurred at the Calgary Stampede.

Monday afternoon during the Novice Saddle Bronc a horse may have had to be put down after apparently breaking his leg at the end of a ride.

The accident happened after Steed Cline of Olds was bucked off Snider Mountain, one of the Calgary Stampede stock.

The horse continued to buck after the ride, then fell to the ground.

Veterinarians quickly attended to horse and tarps were brought out to surround him.

Within a few minutes Snider Mountain was taken away by the animal ambulance.

The Calgary Stampede has not confirmed that the horse was euthanized.

Monday morning a Chuckwagon horse died of a heart attack during a training practice.

And Sunday evening a horse died and a rider was injured during the Cattle Penning competition.

Stampede officials say a horse likely had a heart attack during competition.

Dennis Rach, one of the Stampede Veterinarians says, "The horse was already gone when I checked it out. It was a well, fit horse, in good condition. We generally see it in those kinds of horses because they're the ones competing."

When the horse went down, witnesses say it fell on its rider, Amy Carver.

Paramedics took the rider to hospital were she is in critical condition with a head injury.