The investigation into the massive fire in downtown St. Catharines, that destroyed the historic Welland House hotel, is proving to be difficult.
Chris Lawson with the Office of the Fire Marshall tells CKTB, it is an 'incredibly difficult investigation.'
"We usually follow fire patterns to narrow down the origin, but since the building collapsed on itself, it makes it hard. We are relying on video and witness statements."
Lawson says they believe the blaze started to the 3rd floor, on the south side of the building.
The building did not have electricity running at the time of the blaze, and investigators are even looking into whether lightning struck the building.
Human intervention is also a possibility, with Lawson saying police did receive reports of people in the building.
A student residence closed at the site in 2018, and it had been vacant since.
The Welland House, located at 30 Ontario Street, was a downtown St. Catharines landmark since 1856.
It was destroyed by the fire in the early morning hours of Monday, July 12th.
Lawson admits a cause of the fire may never be known, but they will continue their work.
He encourages anyone with information, who hasn't contacted investigators, to call 1-800-565-1842.