The barn fire that killed 43 harness racing horses at a Puslinch training centre last January was caused by accidental electrical failure.
The Ontario Fire Marshall's office has concluded its report and investigator Manny Garcia said that the fire was definitely accidental.
"The cause was accidental as a result of electrical failure in the northeast section of the barn," Garcia said Tuesday in an interview.
The cause was officially an "energized electrical source."
While investigators weren't able to narrow it down to a specific source, he said there were small appliances, such as a coffee pot and microwave, and extension cords being used in the area that "aren't recommended for use in a barn."
Investigators determined there was no evidence of foul play.
"There was no evidence whatsoever of a crime," Garcia said.
"As much as you don't want to think that somebody did something nefarious, it has to be eliminated."
A variety of investigative methods traced the start of the fire to an electrical failure in the northeast section of the huge barn that contained the horses.
The level and depth of damage in that location, eyewitness accounts and the condition of metal in that location compared to others were some of the investigative tools used to pinpoint where the fire started, Garcia said.
Forensic testing deemed there were no combustible materials used.
Classy Lane is a highly-regarded harness training facility that covers 135-acres on Concession 1 in Puslinch Township, roughly 10 kilometres south of Guelph. At the time of the fire it housed 220 horses.
The fire started in an 11,500 square-foot barn on Jan. 4 at around 11 p.m.
A neighbour also saw flames and called 911. A groom returning to the barn after a night of racing at Woodbine in Toronto also discovered it around the same time.
Fire departments from several municipalities battled the fire for hours in temperatures around -20 C.
It quickly engulfed the older structure, which had no sprinkler system, but firefighters did manage to prevent it from spreading to other barns.
Garcia said the Centre For Forensic Sciences in Toronto, the Ontario Fire Marshall's Office, forensic fire protection engineers and the University of Guelph were all part of the lengthy investigation, Garcia said, adding that he was on site for four days.
"It was just a tragedy all around," said Garcia, adding that it "could have been a lot worse" had people entered the barn to try and attempted to save the horses.
Classy Lane's owners have since rebuilt the barn with state-of-the-art fire detection and protection systems.