A woman has been charged with impaired driving after a vehicle slammed into a home in southwestern Ontario and hit a gas line, causing a major explosion that injured six first responders and one civilian and sent residents fleeing from their homes.

During a press conference early Thursday morning, London Police Chief Steve Williams said they received reports that a vehicle had struck a home on Woodman Avenue, in the city’s east end, at approximately 10:40 p.m. the night before.

When officers arrived two minutes later, Williams said it was immediately evident that a vehicle had struck a house and a gas line.

The female driver, the vehicle’s lone occupant, was arrested and taken into custody on suspicion of impaired driving, the police chief said.

Daniella Alexandra Leis, 23, of Kitchener, has been charged with four counts of impaired operation causing bodily harm and impaired operation of a vehicle with a blood alcohol level exceeding the legal limit. She has been released from police custody and is expected to appear in London court on Sept. 4.

None of the allegations have been tested in court.

Police said 12 minutes after arriving on scene, there was a “massive explosion” that involved a number of residences while police officers and firefighters were still on the scene. There was no one inside of the home that was hit by the vehicle, according to police.

The explosion forced the evacuation of approximately 100 homes located on Woodman Avenue, Quebec Street, and Charlotte Street, but as of Thursday evening, all but 12 families were allowed to return home.

The remaining 12 homes are those in the area closest to the explosion, the City of London said. The other homes have had their water and hydro restored, while the homes on Woodson will be without gas until the morning. 

The city is urging anyone not from the area to refrain from visiting to allow the resident access to their homes.

Tyler Bilyea told CTV News London he was three houses down from the site of the accident when the explosion occurred.

“The building blew sky high, glass coming out from other buildings,” he said. “It was a fireball.”

Another neighbour, Michael Peckham, said he ran out of his house when he heard the vehicle slam into the house. He said he saw a woman behind the wheel who appeared to be unconscious.

Peckham said first responders told him and others to back away as far as they could. He said he was helping a senior couple evacuate their home when the blast happened.

“All of a sudden, all of the windows imploded in their house,” he said. “It was pretty scary.”

Keara-Lynn Douglas told The Canadian Press she was watching TV at around 11 p.m. when she felt her house shaking. She drove a few blocks over to where the explosion occurred and said she saw bright orange flames. The sight of the damage brought her and a group of witnesses to tears, she said.

"One of the homes was completely gone," she said. "There was just debris everywhere."

Two police officers and four firefighters were injured in the blast, officials said. A civilian was also injured and transported to hospital.

EMS Operations Supervisor Adam Bennett said they assessed and treated 12 people at the scene and transported seven to hospital, including the first responders.

Williams said the police officers received minor injuries and have since been released from hospital.

London Fire Chief Lori Hamer said three of the four injured firefighters have also been discharged from hospital. The fourth firefighter remains in “serious but stable condition,” she said.

It’s unclear if the civilian has been released from hospital yet, but officials said they had minor injuries.

The explosion caused a large fire that spread to several other homes.

“At this point, we know of approximately 8 to 10 homes that are severely impacted,” Hamer told reporters.

At the height of the fire, Hamer said they had 16 fire trucks, which equates to 50 firefighters, on scene. She said 20 firefighters are still there working to extinguish the remaining fires, but they’re all “under control.”

“There are still some hot spots that are burning,” she told CTV News Channel on Thursday.

Hamer said the Ontario Fire Marshal arrived at the scene this morning to investigate. She said they’re working together to assess the damage and ensure the site is safe.

The mayor said 28 displaced residents were received at the Carling Heights Community Centre overnight, but they have all been provided with accommodations since and the centre is no longer being used.

Williams said many neighbours in the area ran out of their homes as soon as they heard the collision.

“There was a lot of noise and commotion in the area so people self-evacuated and we assisted others in evacuating,” he said. “People came out of their homes.”

As many displaced residents left with just the clothes on their backs, local businesses have stepped up to provide clothing and food donations.

“This is our neighbourhood too and these are people who are in here all the time,” said Gavin Anderson of Anderson Craft Ales, who has been gathering donations of household supplies. “It was only a couple hundred metres from here, so everyone's been affected by it and we just want to help any way we can.”

On Thursday morning, Enbridge Gas tweeted that service to homes in the neighbourhood had been shut off as a “safety precaution.” The company said it would restore service once they’re given permission by authorities and that it could take “some time.”

Once residents are allowed back into their homes, Donaldson Heating and Cooling has offered a free gas line inspection to anyone affected by the blast.

 “(I) felt I needed to do something and this is something I can do,” said Owner Jamie Donaldson.

The mayor thanked first responders for the quick actions and the community for supporting each other during the emergency.

Holder said he spoke to “a number of residents” who were impacted by the incident – including a man and his wife who were “in tears” at a shelter after emergency services rushed them out of their home.

The man told Holder that he “didn’t know what would have happened if they [emergency services] would have been a minute longer…we got out with our lives.”

Holder added that the Ontario Fire Marshall’s Office had been called in at day break and remained on scene to assess the situation.

The fire chief said they were “very lucky” nobody was killed in the explosion.

“The home that did explode, no one was home at the time,” Hamer said. “Every emergency service that came to assist, police, fire, and ambulance, all worked very well together to mitigate the situation as quickly as possible.”

With files from CTV News London and The Canadian Press