The roof collapsed at an Okotoks horse boarding facility on Monday.
Morgen Langner, the operations manager with JM Equestrian, said they started hearing loud noises at around 9 a.m.
At first, she said they thought it was ice sliding off the roof, but the noise got progressively worse throughout the day.
At around 4:30 p.m., her colleague Ryan Davis went up into the attic area of the building to have a look.
“He came out and said, ‘You need to get out, it’s not good,’” she said.
A quick decision was made to evacuate the building, and all of the animals were moved to a safe distance.
“We had the entire place empty….within eight minutes,” she said.
At around 4:48 p.m., just as the last person was exiting the building, the roof came crashing down.