Five horses died as a result of an accidental fire that erupted in a rented barn on Innisfil Beach Road shortly after midnight on Wednesday.

The horses died from smoke inhalation, Innisfil fire prevention officer Mike Symes said.

Investigators believe a heater placed in the barn by the owner in an effort to keep the animals warm during the current cold snap may have caused the blaze.

“It was an unfortunate accident,” Symes said. “There’s nothing suspicious.”

At about 12:45 a.m., a passing motorist spotted flames and smoke coming from the structure on the south side of the road at 1623 Innisfil Beach Rd. west of the 20th Sideroad.

Two dozen firefighters from two Innisfil fire halls responded to the fire, said deputy chief Tom Raeburn. They battled the fire under bitterly cold conditions, as well as numbing wind chill he said.

Water runoff from the fire hoses quickly turned to ice, covering Innisfil Beach Road and requiring police to reroute traffic between Yonge Street and the 20th Sideroad to the 7th or 9th Lines.

It was a constant challenge keeping some of their equipment functioning in the frigid weather, Raeburn added.

“The guys did a fantastic job in horrible cold and windy conditions,” he said.

Innisfil Beach Road was re-opened for commuters and other traffic soon after 6 a.m.