Police investigating an explosion in Mississauga that killed one woman and forced dozens out of their homes say they are continuing to search the scene for evidence that would point to how the incident occurred.

The explosion completely leveled a home on Hickory Drive, in the area of Rathburn Road East and Dixie Road, just before 4:30 p.m. Tuesday. Several people sustained minor injuries when the blast sent debris flying hundreds of metres in every direction.

At a news conference held Wednesday afternoon, Mississauga Fire Chief Tim Beckett told reporters that residents will not be returning to their homes until at least tomorrow.

However some residents were allowed to return Wednesday evening after police shrunk the perimeter around the blast.

Beckett said investigators want to capture all the evidence “safely and systematically” and that it is likely that they would remain on scene until the weekend.

Ontario Fire Marshal Supervisor of Investigations Jeff Minten told media at the conference that “anything found in the area will be treated as serious.”

Peel Regional Police Chief Jennifer Evans told reporters at an earlier news conference the same day that pieces of paper with “possible information” were found in the surrounding area of the blast and have been handed into investigators. Evans would not confirm the nature of the notes but said that it is something police are looking into. She added that it is too early to tell if the notes are related to the incident or if the blast was deliberate or accidental.

“Citizens have reported seeing some pieces of paper with possible information to the cause of this incident and they have been handed into police,” Evans said.

However, police said later on Wednesday that “There’s nothing to connect the letter to the house.”

“We’re working on connecting it to wherever it belongs,” Sgt Josh Colley said. “We’re not specifying what’s on that paper.”

Colley said said that the homicide unit is not involved in the investigation and officers are not looking for suspects.

The body of a woman was found in the blast zone, Mississauga Fire Services confirmed Wednesday.

The identity of the victim has not yet been released as investigators work to notify next of kin.

According to paramedics, 12 patients who suffered cuts and bruises were treated on scene and released. One person, who also suffered minor injuries, was taken to a local hospital.

Search and rescue teams scoured the area and said there were no other casualties of the blast, Mississauga Fire Chief Tim Beckett told reporters at a news conference.

“We had Toronto HUSAR (Heavy Urban Search and Rescue) come in to do some reconnaissance on the site last night” he said. “At that point in time, they were able to get dogs into the structures that we were unable to get into with actual people. The dogs go in to look for the scent of live victims. We now have people accountable on both sides of the blast zone. That was good news we received last night.”

Minten noted the size of the massive debris field and said the community was “fortunate” there weren’t more people injured.

“The devastation is pretty significant, however it is relatively contained to the immediate vicinity,” “I think it is fortunate that there aren’t more injuries.”

An estimated 25 homes were impacted by the explosion, six of which were heavily damaged. According to officials at the scene, 12 houses and three townhouses were evacuated and utilities were shut off at 58 homes in the neighbourhood.

By Wednesday morning, Beckett said the evacuated perimeter had shrunk by “at least a third” of what it once was. It is now bounded to the area of Rathburn Road to the south, Hickory Drive to the north and Dixie Road to the east.

The addresses still affected by the evacuation include buildings at 4222 Dixie Road, 1359 Rathburn Road, 1355 Rathburn Road and all homes on Hickory Drive.

Residents displaced by the blast have been told to register at the Burhamthorpe Community Centre, located at 1500 Gulleden Drive. At the news conference Wednesday afternoon, Mayor Bonnie Crombie said calls to 311 have been minimal and urged residents to dial the number to let the city know they are “OK and accounted for.”

At the community centre, arrangements can be made to retrieve pets and medications. The Red Cross and the Insurance Bureau of Canada are also on site.

Crombie said she would be going to the centre after the conference to ask residents what they need. She said Salvation Army will be accepting “new and gently used household items and furniture for those that have to rebuild.”

The community centre will remain open until about 11 p.m. tonight, when investigators expect many residents displaced by the blast will be allowed back into their homes.

St. Basil's Elementary School in Mississauga sent out a note Wednesday morning confirming that the school would be closed today due to the explosion.

Residents were told Tuesday night that they can expect to be away from their houses for “a significant period of time.”

Crombie said she was pleased to see how the community came together to help one another.

"Neighbours all opened their doors to each other. It was wonderful to see," Crombie added.

"There was a lot of uncertainty. What happened? Why did it happen? Will it happen to us?"

One witness at the scene told CP24 Wednesday that the impact of the explosion, which occurred shortly before 4:30 p.m. Tuesday, blew his living room shutters off the hinges.

He said he was on the phone with his daughter when he heard a "loud, sharp bang." He said his phone immediately went dead.

"I’ve never heard anything like that before," he added.

"I thought it was the end of the world or something."

Multiple people reported seeing a large cloud of dust rising into the air following the blast.

At the height of their response, Beckett said 50 firefighters and approximately 15 paramedics were called to the initial scene.