UPDATE: Cause of fatal Caledon house explosion believed to be natural gas

It appears the cause of the house explosion in Caledon has been traced back to natural gas.

But CTV is reporting, the office of the Ontario Fire Marshall can't say whether or not the blast was deliberate or accidental.

No criminal charges are expected to be laid.

A 54-year-old man was killed in the explosion and dozens of people have been forced from their homes because of the damage it caused.

More to come...