Residents survey the damage after a storm and a suspected tornado struck Leamington, in southwestern Ontario, early Sunday. (Susan Pedler/CBC)

Residents and work crews have started to clean up the mess in Leamington, Ont., a town near Lake Erie that was hit by a severe storm around 3 a.m. ET on Sunday.

Town officials declared a state of emergency after a suspected tornado caused widespread damage, which will enable Leamington to apply for provincial emergency funding.

Town officials believe the community was hit by a tornado, although Environment Canada has yet to confirm that.

Rob Schmidt, deputy mayor of the town of about 30,000 people, said whatever tore through the region had "all the earmarks of a tornado."

"Quite frankly, we don't care whether it was a tornado or a microburst, the damage is there and we have to deal with it," he said.

No injuries were reported, but damage to property was extensive. Many roads were impassable due to trees and debris.

Power lines were knocked down and about 15,000 customers were without electricity. Crews were working to replace lines, but some residents could be without power for days, said Anne Miskovsky, an emergency communications officer.

Most phone service was restored by Sunday afternoon.

Some of the worst damage is along a section of Seacliff Drive in an older neighbourhood of cottage-like homes, many now severely damaged or destroyed by uprooted trees.

Heavy damage was also reported in Marina Park.

Workers start to clear trees blown down across a Leamington street. (Submitted by Tony DeSantis)

Town officials have opened a recreation centre for displaced people.

Diane Gleason was asleep when the storm hit, but woke suddenly to the clatter of the storm. Soon, the winds toppled a 15-metre-high tree in her backyard.

"It was pretty scary, very loud. There were a couple of claps of thunder that woke me up. Then the winds started to pick up and the trees were just swaying back and forth."

Gleason, along with her son and daughter, ran into the hall of their home, then headed downstairs.

The winds were strong enough to knock down large trees. (Submitted by Michelle Grondins Impens)

"As we ran to the basement we could see that blue spruce fall," she said. "Luckily, we're all safe. There's no damage to the house, but there is a lot of damage around us," she told CBC News.

Barricades have been erected to keep people out of areas where there are downed power lines, broken glass, debris and the possibility of falling tree limbs.

"The affected area is a fairly narrow area along the lakeshore," Schmidt said.

"There are literally thousands of trees that have fallen — some very large, mature trees — on houses and cars."

There are reports that some tomato greenhouses were destroyed just outside the town.

Leamington, about 50 kilometres southeast of Windsor and just north of Point Pelee National Park, is known as the tomato capital of Canada and much of the crop is grown in greenhouses.

Just across Lake Erie near Toledo, Ohio, a tornado killed seven people several hours earlier. At least 50 homes were destroyed in a 100-metre-wide band that stretched about 11 kilometres southeast of the city.

Lake Township Police Chief Mark Hummer said at least 50 homes were wrecked.

With files from The Canadian Press and The Associated Press