GUELPH -- Investigators have now ruled out an external gas leak as the cause of an explosion that destroyed a Guelph home.

Enbridge tells CTV News that its workers were able to access a meter set at the site Saturday. They ran a successful pressure test which helped them determine that an external gas leak was not responsible for the incident at 32 Southcreek Trail.

The Technical Standards and Safety Association will now be taking over the investigation and will be looking at factors inside the home to determine the cause of the explosion.

Enbridge also tells CTV News that they have restored natural gas service to all affected homes.

Friday afternoon’s explosion at a home on Southcreek Trail prompted an evacuation of many nearby homes.

That evacuation order was lifted just before 10:30 p.m. Friday.

Fire officials tell CTV that at least one person was in the house at the time of the explosion.

Guelph police say that the woman, 41, and her dog were both able to escape without injury. She was taken to hospital as a precaution.

Erick Li lives in the house next to the one that exploded.

"I got a phone call from my wife, she was in the house while it happened, and she feels like, 'Is it an earthquake?'"

Fearful, she began gathering as many of their things as she could, which is when she saw the house.

He says his wife is scared but that they're glad that everyone is okay.

“Oh my God how did this happen?” said Boris Zrilic, who lives on the street. “There’s no more house.”

The home was seriously damaged in the blast. Other surrounding houses also sustained minor damage.

“It’s very unfortunate that something like this happens,” said Deputy Chief Dave Elloway of Guelph Fire. “However in this particular case we could not have had a better outcome in that the individual who was in the house escapes with no injuries.”

A Fire Marshal’s Office investigator echoed what many responders were saying: it’s amazing nobody was seriously injured.

“It’s unbelievable, when you look at the fact that they came out of a two-storey home that is now less than one storey; it’s kind of pancaked on top of itself, it’s unbelievable,” said Manny Garcia, a supervisor with the Ontario Fire Marshal.

It's not yet clear what caused the explosion.

“Obviously there has been some type of natural gas explosion,” said Garcia. “The question is how did that happen and how was the natural gas introduced into the structure that caused it to explode? That is what we are trying to figure out.”

A representative from Enbridge says that before they restored service to homes in the area, they inspected all gas meters and appliances to make sure they were operating safely.

“We’ve tested the line, it’s absolutely intact, and we’re not getting any sort of gas leak,” said Garcia. “This appears to be an isolated incident.”

Police say that all of the houses on the street were evacuated as a precaution and utilities were shut off in the area.

“At about 10:15 p.m. we got the message that we could come back,” said Wyatt Cholack, who lives on the street. “We came back to the house and everything was good and fine.”

Parent Andrew Weeks says he is now trying to explain to his children what they heard and saw as well as reassure them that the neighbourhood is safe.

“You try to put on a straight face and say to them you know there’s nothing to worry about,” he said. “There was something wrong with that house but there’s not at our house.”

The Fire Marshal’s Office says it’s hard to know when answers will come, as it depends on what is found and what needs to be sent off for testing.

“If there is anything to be learned here, it’s that natural gas is not to be played with or taken lightly,” said Garcia. “Any sign of that smell – that rotten egg smell – get out of the house and call 911”, he added.