A ferocious storm system moving eastward through southern Ontario spawned at least two possible tornadoes in the GTA, caused the city of Vaughan to declare an emergency and left one person dead in a small Grey County community.

Thursday's death came in Durham, a small community south of Owen Sound, according to the West Grey Police Service.

It's complete destruction," said resident Gord Becker. "The sky was just black; the clouds were moving in circles. There was tremendous amounts of tree damage, wires were down -- I just barely got through the road."

Some reports indicate the person died in the Durham Conservation Area, a park to the north of the town.

"All the trees are down around my trailer," Brenda Ailles, camping at the area, told CTV News. "There were people in tents. Everything got swept away."

The same system that hit Durham with a possible tornado moved northeast to strike at the Blue Mountains near Georgian Bay.

In the GTA, no deaths were reported, but tornadoes are believed to have touched down in Vaughan and Newmarket.

The first report came in from the Royal Canadian Riding Academy in Newmarket. About 400 people there for an equestrian event say they saw the suspected tornado flip cars.

One group of people told CTV personnel on the scene they took shelter in a horse trailer -- one that got lifted up and spun around 180 degrees. But they emerged with nothing more than scratches.

Another man reported seeing a pony get lifted up by the storm.

However, no serious injuries were reported to either humans or horses. The grounds themselves did suffer damage, as did vehicles.

Vaughan damage

About a half hour later, TSN's Gord Miller told CTV Toronto from his car on Highway 400 that he saw a funnel cloud touch down in the Highway 7 area to his west. Lightning strikes around him were "coming every five or six seconds."

Cheryl McNeil, a Woodbridge resident, said: "I was feeding my son, and my mother said, 'Look out the window, Cheryl, look at the trees.' And all I saw were tree branches and garbage -- and this huge funnel cloud is right in the back park behind my house."

York Regional police said they sent every available officer to Vaughan to help with the storm aftermath.

But while there was widespread damage, along with power outages due to downed lines, they didn't know of any serious injuries, they said.

"We know there's a lot of property damage ... we're still trying to just keep things under control," said a police spokesperson.

Images from the scene show homes with all their shingling stripped off by the wind. In a few cases, homes lost their roofs altogether.

Some peoples' homes were heavily damaged by falling trees. One person said their neighbour was doing their dishes when the storm blew their windows out.

Other people out wandering after the storm to check the damage told CTV News they had absolutely no warning. One firefighter with nearly three decades experience said he's never seen anything like this.

Shortly after 10 p.m., the city of Vaughan declared an emergency. It reported that 120 homes have been evacuated.

"The evacuation centre is Father Ermanno Bulfon Community Centre at 8141 Martingrove Road in Woodbridge. The Red Cross is assisting this effort," it said. The emergency number to call is 905-832-2281.

York Region Fire Chief Greg Senay said from a helicopter, one can see that hundreds of homes have been damaged. "It was an awesome display of power," he said of the storm.

Despite the physical damage, the city confirmed were no serious injuries or fatalities in Vaughan.

Mayor Linda Jackson said it was a miracle no one died.

Toronto police didn't report many problems, but Toronto Hydro had a high volume of calls. Toronto Fire had also responded to a number of "wires down" calls. Some older trees got knocked down.

What happened

CTV Toronto weather anchor Tom Brown said the high energy of the storm system resulted from a cold front meeting warm, humid air.

"That spawns off thunderstorms and those thunderstorms, if conditions are just right, can spawn off tornadoes," he said.

The system continued on to eastern Ontario into the evening, but Brown said it should lose energy as the air cooled.

At 9:41 p.m., all weather warnings and watches were ended for Toronto.

Environment Canada's Geoff Coulson said Environment Canada teams will head out Friday morning to confirm whether tornadoes occurred. Some of the damage could be from downbursts associated with severe thunderstorms, he said.

Prime Minister Stephen Harper, currently touring the Arctic, said:  "We share our thoughts and prayers with any who have lost lives or have dislocation because of this. Obviously the government of Canada, where appropriate, will work with local and provincial authorities to deal with this situation."

With reports from CTV Toronto correspondents and files from The Canadian Press