Fire investigators are dismantling the twisted metal wreckage of a stable destroyed by a fire that killed dozens of horses in Puslinch, Ont.

The fire began at approximately 11 p.m. on Monday, at the Classy Lanes Stables Training Centre, located in the township approximately 20 kilometres southeast of Guelph.

More than 200,000 gallons of water were trucked to the location by firefighters from surrounding communities, but the blaze could not be extinguished in time to save the animals.

Most of the roof collapsed, and parts of the walls fell in on the flames. All 43 horses that were in the barn when the fire began were trapped, and died in the blaze. The loss of the animals along with damage to the property amounts to an estimated $4 million to $5 million.

Firefighters worked overnight and all day Tuesday extinguishing the fire and monitoring hot spots. Tractors were brought in Tuesday afternoon to clear some of the debris.

On Wednesday morning, investigators with the Office of the Ontario Fire Marshal could be seen combing the site, sifting through rubble and documenting discoveries. Dozens of yellow tarps were strewn across the barn floor, covering the bodies of the horses that perished.

By noon, crews were working to remove the horses' bodies and dismantle part of the collapsed barn. Many have left flowers and stuffed toy horses along the fence of the facility in memory of the horses that died.

The cause of the fire is not yet known, and local fire crews are working with the OFM and provincial police to investigate. The stable was assessed by an electrical engineer in the fall and had passed the inspection, officials told CTV Toronto.

Investigators are focusing on the east end of the stable, where an office contained several appliances and baseboard heaters. However, they have not confirmed whether the fire began in the office.

As crews searched the property, trainers could be seen using the facility's tracks to exercise the horses that live in the centre's other four barns, which were unaffected by the fire. Horses and trainers could be seen from the CTV News chopper racing around an oval track located next to the barn where dozens died.

The majority of the horses housed at the facility are owned by trainers, who race them at southern Ontario racetracks including the Mohawk, Woodbine and Flamboro Downs tracks.

Several crowdfunding campaigns have been set up for those wishing to contribute to those affected by the fire. Many did not have the majority of their horses insured because of the high cost.

With a report from CTV Toronto's John Musselman