The home explosion in Mississauga, Ont., that killed two people and destroyed much of the residential neighbourhood in June was intentional and has been ruled a double suicide, Peel Regional Police Chief Jennifer Evans announced Friday.

The announcement was made at a news conference at Peel police headquarters, explaining a blast that killed married couple Diane Page and Robert Nadler, the owners of the home.

"We hope this will provide some answers and much needed closure to those most closely impacted by this tragic event," said Evans.

Kevin Pahor of the Office of the Ontario Fire Marshal told reporters the explosion originated in the basement of the house and there was an "intentional" disconnect of the natural gas piping from the hot water tank in two locations, allowing gas to build up explosive force.

Neighbours said they smelled gas for more than 90 minutes before the explosion, according to Pahor.

The ignition source could not be identified.

Kevin Pahor, right, of the Office of the Ontario Fire Marshal, stands with Mississauga Mayor Bonnie Crombie. Pahor told reporters the explosion originated in the basement of the house and there was an 'intentional' disconnect of the natural gas piping. (CBC)

The explosion occurred on June 28 in a home at 4201 Hickory Dr., in Mississauga, about 30 kilometres west of Toronto. The bodies of Page and Nadler, both 55, were later found amid the rubble. Several others in the area suffered injuries.

Evans said the cause of death was blunt-force trauma as a result of being near the epicentre of the blast. She said a toxicologist confirmed both Page and Nadler were alive before the explosion.

She said investigators identified four possible scenarios for how the explosion started:

Accidental

Double murder

Murder-suicide

Double suicide

Evans said the investigation found the explosion to be intentional and that supporting evidence ruled out the other three possibilities.

The explosion occurred on June 28 at a home on Hickory Drive in Mississauga. The bodies of the owners, Diane Page and Robert Nadler, were later found amid the rubble. (CBC)

Disturbing notes found at scene

Investigators said Friday notes found near the scene of the blast were likely written by Page. The letters were found by neighbours shortly after the blast and contents of the letters were said to be disturbing.

Residents who read the notes told CBC News in June the wording was apologetic in tone. They said the writer described being in pain, asked God for help and, according to at least two different residents, requested forgiveness for the writer's future actions.

Investigators said Friday notes found near the scene of the blast were likely written by Diane Page, pictured above. The letters were found by neighbours shortly after the blast and contents of the letters were said to be disturbing. (Submitted by Paul Camilleri)

"They were apologizing for what they were about to do and [said] 'dear Jesus, please forgive me,'" said Rhonda, who found a shopping bag full of letters in her yard. She would only give her first name.

A second letter shown to CBC News in June also mentions health challenges and includes an apology for the writer's inability to keep up with home maintenance and cleaning.

"I trust God to look after me and my husband to take us home," the writer says.

Investigators said Friday there was no evidence that either Nadler or Page had cancer, as Nadler had told a neighbour.

Dozens of neighbourhood homes still vacant

Mississauga Mayor Bonnie Crombie previously said 33 homes in the area remain empty six months after the explosion.

Crombie had said a "team of professionals from the City of Mississauga remains engaged with those families impacted."

Area Councillor Chris Fonseca had been hosting community meetings for families not yet back in their homes.

Mississauga Mayor Bonnie Crombie said another community meeting will be hosted in a couple of weeks for families not yet back in their homes. (CBC)

Some homeowners are facing both mortgage and rent payments, according to Fonseca, as some insurance coverage has run out. Four homes were demolished, leaving their owners to go through lengthy rebuilding processes.

Speaking with CBC News on Friday after the press conference, Crombie said she remains committed to homeowners and residents affected by the explosion.

"The city is working with the residents and all the utility companies and the Insurance Bureau of Canada," she said.

Crombie said another community meeting will be hosted in a couple of weeks "so we can get all vital parties together to answer their questions."

Speaking with <a href="https://twitter.com/CBCToronto">@CBCToronto</a> Alison Chiasson about <a href="https://twitter.com/citymississauga">@citymississauga</a> efforts to support Hickory families that remain displaced. <a href="https://t.co/dlkduFE8An">pic.twitter.com/dlkduFE8An</a> —@BonnieCrombie

She acknowledged the complicated nature of the situation, and said the meeting aims to "put some pressure on the insurance companies to move along."

"Each individual case is different because the amount of damage is different to each property," said Crombie. "The type of insurance coverage is different, each have different policies with different companies."

The meeting is to "ensure we're working with Insurance Bureau of Canada, so they can be the advocate for the resident," she added.