Sixteen horses were killed when a fire broke out at Sunnybrook Stables in Toronto early Monday morning, fire officials said.

Firefighters arrived on the scene around 3 a.m. to find one of the barns on the property consumed by flames.

About 50 firefighters battled the blaze, but they were unable to save the barn or the 16 horses inside.

“It’s a tragic and sad day,” Toronto Fire Chief Matthew Pegg told reporters. “This has been a landmark in this area for a long time.”

Firefighters also worked to keep the fire from spreading to a nearby building. They managed to get 13 other horses to safety.

Mounted police helped search the surrounding Sunnybrook Park area for other horses.

Investigators have yet to determine the cause of the blaze. Pegg said there is an initial report of fireworks in the area Sunday night and early Monday.

“That is something that the Office of the Fire Marshal and police are aware of,” he said.

Sunnybrook Stables offers private and group horse-riding lessons, as well as summer camps. The loss of 16 horses was devastating news for the city’s equestrian community.

“I was really upset; I was crying a lot,” 14-year-old Richard Sutton, a regular rider at Sunnybrook Stables, told CTV Toronto.

The teen had plans to ride at the stables on Monday before he found out that many of his favourite horses had died in the fire.

Toronto Mayor John Tory said he recalls riding his bike to visit the stables as a boy.

“It was a great adventure to come to see the horses,” he told reporters. “When they die in tragic circumstances like this, I think people are very much affected by that.”

The 13 horses that were saved from the fire are being temporarily housed in stables at Exhibition Place.

Investigators from the Ontario Fire Marshal’s Office were called to the scene to help determine how the fire started.

With a report from CTV Toronto’s Scott Lightfoot and files from The Canadian Press