Broken walls, windows and other debris fill a street after a tornado touched down Thursday on the edge of Durham, Ont. (Dave Chidley/Canadian Press)Ontario began a long cleanup process after at least four suspected tornadoes left a trail of debris and damage in several communities, officials said Saturday.

An 11-year-old boy died at the Durham Conservation Area about 50 kilometres south of Owen Sound during the storm, West Grey Police Service Chief Rene Berger said at a news conference in Durham.

The child was from West Grey, but his identity was withheld at the family's request, Berger said. Police declined to provide further information on the death, but it is believed the boy was killed by debris.

A number of other people at a day camp at the conservation area were hurt by the storm and they were taken to hospital, said Mike Muir, manager of Grey County EMS. They were later released.

Across the street from the conservation area's entrance, damaged homes included a brick bungalow owned by Arthur and Shirley Campbell, said their son, Anthony Campbell.

"The tornado came up their driveway and completely destroyed the house," Campbell said in an email. Both parents were unhurt except for some cuts and bruises.

Crews assessing damage

Durham acting mayor Dan Sullivan said, "Our thoughts and hearts are with those that have been impacted by this event."

He said Durham is now in the recovery phase, adding, "we do have months of work ahead of us to remove some of the scars on the community."

Police officers talk near a building destroyed by a tornado that hit the edge of Durham. (Dave Chidley/Canadian Press)In Vaughan, no one was injured, but Mayor Linda Jackson said Friday that about 600 homes were damaged. More than 200 of those are deemed to be unfit for habitation as they currently stand, including 44 with "restricted occupancy" that will have to be demolished.

A state of emergency remains in the City of Vaughan and officials were meeting Saturday to determine when that might be lifted.

"The devastation was certainly catastrophic," said Jackson at a news conference after touring the affected areas. "I've lived in Vaughan for more than 40 years. I've never seen any devastation like this."

A lot of residents are in a state of shock, she said, adding, "they're now realizing with daybreak how much devastation and how lucky they are to be alive."

Public Safety Minister Peter Van Loan said the fact that damage was not as extensive as it could have been, given the intensity of the storms, is a testament to the area's emergency response teams.

"This site is in a lot better shape now than it was even 12 hours ago," he said. "In this case they applied the [emergency response] plan, they used it and it worked perfectly."

Inspections continue

Communities worst hit by the string of twisters that whipped through Ontario this week will have to wait to see if they qualify for federal aid, Van Loan said. The decision is not a political one, but rather the result of a complex mathematical formula, he added.

Fourteen building inspectors were sent to assess the damage in the four affected areas in Vaughan, Jackson said. Those inspectors returned to the community on Saturday to assist residents.

Two emergency shelters remained open Friday night to assist displaced residents, although she said nobody needed the shelters on Thursday. She surmised that people out of their homes were opting to stay with family or friends.

City officials couldn't provide a cost figure or an estimate of the number of people whose homes were damaged or destroyed. Jackson said insurance adjusters were on site to help residents.

Tornado evidence

Environment Canada crews were sent to several communities, including Newmarket and the Collingwood area, to assess the devastation left by the violent thunderstorms to determine if spotted funnel clouds were tornadoes.

Photographic evidence makes it almost certain that tornadoes did touch down in Durham and Vaughan, said Environment Canada meteorologist Peter Kimbell, but data must still be collected.

The agency later confirmed that two tornadoes touched down in those areas.

Tornadoes are rated on a scale of 0 to 5 that considers the amount of damage they have caused.

Aerial shot of a damage to a home in Vaughan, Ont., after Thursday night's storm. (CBC)Thursday's storms shut down an equestrian competition at the Royal Canadian Riding Academy in Cedar Valley, east of Newmarket, and sent hundreds of riders looking for shelter in barns and horse trailers.

"All of a sudden just this big funnel cloud came out of nowhere," said Kyle Ecclestone, who works at the academy. "Trees were being ripped out of the ground, trucks and trailers were being flipped over and dragged around, pieces of the roof of our facility were being dragged around. Structures on the property were torn to pieces."

Wendy Chiasson, who sought shelter in the academy's main barn. "I just remember the sound just like when you watch a movie," she said. "It was that loud sort of roar and then a funny whistle. I was in the hallway here and then the glass blew out."

The storm damaged hundreds of buildings, uprooted trees and ripped down power lines. Flights were also cancelled at Toronto's Pearson Airport and major roadways in the Greater Toronto Area were briefly flooded.

The weather instability was caused by a deep trough of low pressure west of the Great Lakes funnelling with a warm, humid air mass over southern Ontario and a wind shear, Kimbell said.

State of emergency

Vaughan and Durham declared states of emergency to mobilize outside help and gain access to funds from provincial and federal agencies.

Ontario Premier Dalton McGuinty, who toured Vaughan on Friday morning, said he was surprised by the power of the storm, which "tossed cars around like toys."

He offered provincial help and expressed sympathy for those affected by the storm, particularly the family of the Durham boy who died.

Prime Minister Stephen Harper said the federal government would be working with municipal and provincial authorities to deal with the storm's aftermath.

"Our thoughts and prayers are with any who have [seen] loss of life or been dislocated because of this," said Harper in a statement Thursday night.

About 1,000 Hydro One customers in southern Ontario remained without power on Saturday morning. Most of those affected should expect to have power restored by the end of the day, Hydro spokesman Corey Labatt said.

At the peak of the outage period following Thursday's storm, 69,000 Hydro One customers were without electricity.

"Significant progress" has been made in restoring power in the Toronto area, Toronto Hydro said, but multiple outages are still being reported. About 4,500 remained without power, down from 25,000 at the storm's peak.

With files from The Canadian Press