Environment Canada officials say that a tornado and a dangerous windstorm known as a downburst may have been behind the widespread damage inflicted on communities southeast of Windsor Sunday morning.

The full force of the storm hit about 3 a.m. and prompted Leamington a city of 31,000 residents to declare a state of emergency.

While there were no reported injuries, trees snapped across the area and one official described the impact as that of a bomb going off.

"Me and my dad heard a really loud noise" around 3 a.m., said Kingsville resident Daniel Zompanti, who rode out the storm in the basement of his home. "It sounded kind of like a china cabinet falling over, a lot of dishes breaking."

Power outages were widespread and later in the day, crews worked feverishly to restore electricity. Most phones were working by mid afternoon. But police were still controlling the storm-damaged area, erecting barricades to keep people away.

"The crews are working 24-7, but unfortunately as we're speaking it's pouring rain," John Adams, the mayor of Leamington, said of the recovery efforts. "The hydro companies can't work very well in the rain."

"It's nice to see that local contractors are on the job repairing roofs that have been destroyed, putting tarps down. The local hardware stores are actually donating chainsaws for residents that want to help clean up their backyard," Adams told CTV News Channel. "The whole community is definitely coming together."

The wind caused damage as far west as Harrow, hit parts of Kingsville and extended to Point Pelee National Park.

Across Lake Eerie, near Monroe, Michigan, a nuclear plant shut down automatically after strong winds tore siding off one of its buildings.

Emergency communications officer Anne Miskovsky described the damage north of the lake as "mind boggling."

"Trees are everywhere, all over the place. It's like a bomb hit it," she said.

The building department was also scouring the area, moving from house to house to make sure no one was in an unsafe situation, said Miskovsky.

The storm started building late Saturday night as Environment Canada issued several tornado warnings for the area throughout the night and into the early morning hours of Sunday.

"Huge trees are severed down the middle and are laying on top of the roads or houses. Hydro poles have been sheared in half and are just lying here," she said.

On Seacliff Drive, a large street near the lake, it looked like bulldozers had clear cut the area.

Picnic tables were floating in Lake Erie outside the badly damaged marina, said Miskovsky.

Environment Canada said it may take until Monday to determine conclusively what types of weather caused the damage.

With files from The Canadian Press and a report from CTV Toronto's Austin Delaney