04/21/2015 09:19 EDT | Updated 07/12/2015 05:59 EDT

Fatal Toronto house explosion probed by investigators

Toronto fire investigators are starting to pick through debris of an explosion that obliterated a house in Scarborough on Monday afternoon and left one man dead.

Adrian Ratushniak of Toronto Fire Services arrived on the scene shortly after an explosion on Port Royal Trail — near Brimley Road and Steeles Avenue East — that was heard throughout the area and felt as far away as Markham.

"The house is completely flattened," Ratushniak said Tuesday on Metro Morning. "There's only a basement you can see."

A man was pulled from the rubble and pronounced dead at the scene. On Monday evening, Toronto police confirmed the identity of the deceased as Paul Zigomanis.

Ratushniak said the Ontario fire marshal will continue to comb through the debris "brick by brick." He said investigators do not know if they will find other victims in the rubble.

"There may be other people involved," he said. "We don't know if the person that passed away was alone at the time. Today is going to be a day that we find out if anyone else is in the home."

The explosion damaged nearby houses. Those adjacent to the destroyed house "will not be occupied any time soon," said Ratushniak. He said in some cases, houses near the blast site may be write-offs.

So what could have caused such a blast? Ratushniak said investigators are looking at possible ignition sources, including:

- A drug lab? "There is nothing to my eyes that indicated anything of that nature," said Ratushniak.

- A natural gas leak? "I've seen other homes over my 26 years that have been damaged as a result of natural gas explosions within the home, however nothing this severe."