Divisional Chief for Fire Prevention Mark Wilson says fire crews had to force their way into the building when they arrived on scene, meaning the building was locked and secured at the start of the blaze. Wilson says he can't speak for whether or not squatters had been there before.
Wilson adds fire crews regularly check vacant buildings to make check they're secure. If they're not, it's up to the owner to make sure the building is safe.
Investigators are still trying to determine a cause, which Wilson describes as "putting together a large puzzle."
