St. Catharines, Ont., firefighters have classified the cause of two fires downtown that started hours apart last month as underdetermined.
The news comes after two weeks of investigation by the fire department and Niagara police, said a city statement Tuesday.
The buildings both had no active utilities and investigators discovered a combustible fuel source was used to ignite the fires, the city said.
But the fire did not spread from one building to another, said fire Chief David Upper.
"We believe the fires originated on the upper floors of each of the respective buildings, but due to the extent of structural damage and demolition required to ensure the fires were completely out, a definitive point of origin couldn’t be determined for either fire," he said in the statement.
2 fires in former St. Catharines Standard building
The first fire began in the attic and roof area at 9 Queen St. around 7 p.m. on Dec. 26, said a news release from the time. The building was previously a restaurant but had been vacant for a while.
"While crews were able to quickly gain control of the fire after a defensive attack, they brought in heavy equipment to pull the building down to allow firefighters to douse hotspots that continued to burn in the roof," the statement said.
The fire was extinguished at about 1 a.m., Dec. 27.
Hours later, firefighters responded to another fire nextdoor in what was left of 17 Queen St. — the former St. Catharines Standard building where another fire had taken place on Dec. 5.
The remains were fenced off for demolition when the second fire broke out.
Investigators haven't been able to link the two fires at 17 Queen St. because of the "severe damage and state of the site after each of the incidents," said Upper.
Investigators have sifted through the rubble of both sites, spoken to neighbours and reviewed security footage, the city said. Anyone with information is encouraged to contact police or Crime Stoppers.
The property owner is continuing to clean up the sites. While the sidewalk out front remains closed, all roads have reopened.