Saskatoon police say a fire that caused extensive damage to a three-storey rental house in Caswell Hill Tuesday night is considered suspicious.

“It’s been deemed at this time an incendiary fire,” said assistant fire Chief Dan Paulsen. The blaze was originally believed to be a result of an electrical malfunction, however, after further investigation there are indications the fire started from the inside the house, said Paulsen.

“It was the temperatures from the inside that lead to the wiring become impacted on the outside,” he said.

Arson investigators from the Saskatoon Police Service and the Saskatoon Fire and Protective Services have now been assigned to investigate the blaze at 109 28th Street West.

Emergency services were initially called to the area Tuesday night after a downed power line in the alley between 27th and 28th Streets West. Police said while the caller was still on the line, he noticed smoke rising from a house across the alley.

Firefighters found heavy smoke inside the apartment and discovered most of the electrical outlets were blackened or burnt.

No one was injured but it’s estimated the blaze caused $100,000 in damages.

With files from News Talk Radio's David Kirton