Hurricane Juan slammed into Atlantic Canada overnight, bringing blistering winds and torrential rains that killed at least two people and left up to 100,000 in the Halifax, Nova Scotia area without electricity.

The storm's devastation was worst in the Nova Scotia capital, where it made landfall just after midnight Monday morning. The category 1 hurricane -- the weakest on the Saffir-Simpson scale -- was downgraded to a tropical storm once it reached land.

But as the storm's peak passed through Halifax around 1 a.m., gusts reaching 143 kilometres per hour proved deadly.

A paramedic was killed when a tree fell on the ambulance he was driving. The incident happened just outside the Queen Elizabeth Two Health Sciences Centre -- the main hospital in downtown Halifax.

Another person died in the town of Enfield when a tree fell on a vehicle there.

And in Dartmouth, the storm's blistering winds caused a section of a four-storey apartment building to collapse. At least three people were trapped inside, but rescue crews managed to get them out safely.

At its height, the swirling storm -- measuring about 300 kilometres wide -- caused a storm surge that flooded low-lying areas of downtown Halifax and forced the evacuation of hundreds.

Businesses along the city's picturesque boardwalk were swamped and giant trees were uprooted from the ground and strewn across roads, powerlines and buildings.

A fishing schooner from Cape Cod sunk at its berth and in Dartmouth, a number of small sail boats have reportedly been beached.

A state of emergency was still in effect throughout the city Monday morning, as Halifax Mayor Peter Kelly urged residents to stay at home if they didn't have to go to work.

"We are encouraging all non-essential personnel to stay at home and let us do what we have to do to get this place cleaned up," he told CTV's Canada AM.

As day broke, clean up crews began their work across the storm's path. In Halifax, power crews were inching their way around downed trees and residents stunned by the unexpected devastation -- with a little help from the city's snowplows, enlisted to help clear the streets of fallen debris.

As for the power outage, Kelly said it is "widespread." He said electricity will likely stay off until at least noon on Monday.

CTV's John Vennavally-Rao, reporting from Halifax, said the biggest problem today is getting around the streets of Halifax because of the downed trees and debris. "Many of the side streets and some of the main roads are impassable this morning."

Firefighter Robert Zinc said the storm was a lot worse than he expected. "I've been here for 40 years and this is the worst I've ever seen it."

P.E.I. lashed by Juan

In Prince Edward Island, winds of up to 139 kilometres an hour uprooted trees and knocked out power to most of the Island, or about 44,000 customers.

School has been cancelled in the eastern part of the province, and delayed until noon in the west. The University of P.E.I. and the province's community colleges were also closed.

Despite the disruption, Charlottetown's acting mayor, Clifford Lee, said the storm won't affect the provincial election.

In fact, CTV reporter Dan Viau said he saw voters arriving at the polling station where he was in Charlottetown-- as soon as they opened.

"The polls in our provincial election are open," Viau told CTV's Canada AM. "They did open at 9 o'clock -- many without electricity."

The province's chief electoral officer said there was no legal way to change the election date because of bad weather.

Tropical storms routinely soak Atlantic Canada each summer and autumn, but a full-fledged hurricane making landfall is rare.

Juan is the fifth hurricane of the Atlantic season, which began June 1 and runs through Nov. 30.

David Phillips, senior climatologist with Environment Canada, told CTV News this year's hurricane season has been exceptional.

"Six months ago forecasters said because of sea surface temperatures and wind patterns this was going to be an active season. It has been really active. We expect in a normal season 10 tropical storms and already we've had 11 ... and we still have two months to go."

Phillips added that the jury was still out on what might be in store for future hurricane seasons.

"We do think there will be more intense hurricanes with warmer sea surface temperatures, but whether there will be more frequent ones ... that's still an issue scientists are working on," he said.

But for staff at the Canadian Hurricane Centre in Halifax, it'll be a while before they are able to submit Juan to a careful analysis.

They were forced out at the peak of the storm when high winds caused the building to sway and windows to vibrate. Monday morning, they were out again as power and water to the facility was cut off.

As Juan -- downgraded to a post-tropical storm -- continues to track across the Gulf of St. Lawrence, most of the storm warnings have been lifted.

Maximum sustained winds are now just over 90 kilometres per hour as the storm makes its way towards Labrador.

With reports from the Canadian Press