Woodbine racetrack reopened to the betting public on Monday as the Ontario fire marshal continued his probe into the cause of Sunday's massive fire, which claimed the lives of 31 thoroughbred horses.

Smouldering sections of Barn 7-7A hampered investigations Monday, but those hotspots should be doused by afternoon, allowing for a full assessment of damages, Toronto police said.

"We know how many horses are unaccounted for now — 29 — and the number confirmed dead," said Sergeant Michael MaManus, "but we really won't know exactly how many horses were killed until the fire marshal completes his investigation. The cause of the fire remains unidentified at present."

Two horses were recovered from the barn late Sunday morning, said John Siscos, a spokesman for the Etobicoke racetrack. They were taken to a veterinary clinic in Guelph, Ont., and later euthanized because of their injuries.

It was shortly before 3 a.m. Sunday that Toronto 911 dispatchers received a call about a blaze in one of the buildings at the Etobicoke racing complex.

Barn 7-7A housed as many as 192 animals, most of which were recovered, Mr. Siscos said. They have been boarded in other barns on the grounds.

That any of the animals are still alive, he said, is owing to the bravery of two grooms, lodged in the barn at the time of the blaze. They were able to release the penned animals and to direct them to safety. It is believed that many of the unaccounted-for horses ran back into the barn, heading for their stalls — places where horses feel especially safe.

Woodbine is home to both harness and thoroughbred racing. It will return to a full schedule of competition at 12:30 p.m. Monday with a thoroughbred race, Mr. Siscos said.

While damage to the barn itself is estimated at $3-million, the cost in horse flesh is expected to compound those losses by at least $40-million.

The owner of the horse that won Saturday night's last race was hardest hit by the fire.

Steve Owens says that his prize-winning horse, Legal Heir, is among the unaccounted for animals, as is Highland Legacy, Canada's colt of the year in 2000.

While the exact cause of the searing blaze is still unknown, the bales of dry hay stored in the barn may well have caused the fire to spread more rapidly, Sgt. McManus said.