By The Canadian Press
Toronto - Investigators say a gas leak caused a massive explosion that levelled a house in northeast Toronto killing one man inside, but they don't know what kind of flammable fuel was involved or where it came from.
At least 40 more homes in the area were damaged in Monday's blast and paramedics say a person from an adjacent house was treated for minor hand injuries.
Wayne Romaine, an investigator with the Ontario Fire Marshal's office, says crews are asking nearby residents whether they smelled gas before the explosion.
He says the cause of the blast could be "migrant gases'' that went through the soil and into the house's basement.
Crews are combing through the rubble for evidence and have brought in a cadaver dog to search for any other people who may have been hurt.
Investigators are expected to be at the site until Friday.
Police have identified a man who was pulled from the wreckage Monday and pronounced dead at the scene as Paul Zigomanis. Romaine says he was found at the back of the house.
Toronto fire Capt. Adrian Ratushniak says several homes in the immediate area were evacuated and the area was closed to traffic.
Photographs by Toronto fire show nothing but rubble left from the house that stood two-storeys tall. Debris was scattered over hundreds of metres, some of it hanging from trees and on neighbouring houses.
Romaine says there is little fire damage to the debris, which suggests the fuel was spent after the explosion.