GUELPH -- The Ontario Fire Marshal is continuing to dig around the debris of a house explosion in hopes of finding answers.

They office of the OFM says they are wrapping up their investigation into what caused the explosion that levelled 32 Southcreek Trail in Guelph Friday afternoon.

They add that they made significant progress on Sunday and are confident they’ll be able to determine what happened soon.

“We’ve been able to identify a number of the gas fire appliances and we’ve made our way into the basement of the residence,” said Manny Garcia, a supervisor for the OFM. “We’ve got our engineers looking at it right now.

“I can say we will more than likely be done today [Sunday] with our investigation.”

Enbridge Gas serviced the house earlier on Friday before the explosion. A rep from the company and the OFM have both ruled out an external gas leak as the source. They conclude the something went wrong from the inside.

An internal natural gas leak can be caused by faulty appliances. The OFM recommends getting appliances such as furnaces and fireplaces inspected and serviced at least once a year.

“If you smell that rotten egg smell then there’s a problem,” said Garcia. “You need to act quickly. Get out of the house and call 911 immediately.”

A spokesperson for the Technical Standards and Safety Authority says part of the investigation is to look at the events that unfolded.

A relative of the people that lived at the home tells CTV Kitchener they’re thankful for all the support they’ve received so far.