Police spokeswoman Anie Lemieux said there may have been a break-in at the house on Marie-Anne-Tison Street in the district of Rivière-des-Prairies in the city's east end.
Lemieux said people were seen running away from the scene after the fire began.
She said the owner of the home was not there at the time of the fire, and it's not believed anyone was injured.
Witnesses saw 'ball of fire'
Shortly after 11 a.m. neighbours reported hearing a loud boom, and witnesses saw a big ball of fire. They said the force of the explosion blew the roof right off the house.
More than a dozen fire trucks were called to the scene to put out the fire, which spread to the house next door.
That neighbouring home was badly damaged.
All that was left of the brick house where the explosion occurred was the charred skeleton of the two-storey building.
Worried that those walls that remained standing could collapse, firefighters brought in a bulldozer late this afternoon to knock down what was left of the structure.
The house was located in a recent housing development, and neighbours said the destroyed building just went up last summer.