ROCKWOOD -- Gusting winds and rain wrecked havoc on a large portion of southwestern Ontario on Sunday.

Thousands of people were still without power on Monday.

Rockwood's Sacred Heart Public School was closed due to a power outage, along with Eramosa Public School.

The Upper Grand District School Board said some of its online classes might also be affected by the storm, because some teachers may not have power to host live sessions.

The storm blew traffic lights, knocked down trees and caused some serious damage in Cambridge. The Cambridge Fire Department said at least one person was hurt when their ceiling collapsed on Sunday.

The wind also knocked down trees at Brookfield Golf Club.

"The damage on the course today was pretty significant," general manager Barb Warry said.

Staff were hard at work Monday to clean up the mess quickly.

"We had the assistant superintendent at Beaverdale come through last night to assess the damage and the staff were out early this morning, just making sure that things were safe for people to play," Warry said.

Golfers were still able to hit the links.

"We're really promoting the idea of being able to have a safe space for people to get out over the next few weeks, months," Warry said.

An empty grain silo under construction in Ayr was also flattened by the winds.

Ayr

"The storm was quite violent for a short period of time," Rockwood resident Bob Watson said. "The wind was very strong and it was raining and the power went off around 3 yesterday afternoon."

It's been dark at his home ever since.

"Our cell phone service isn't working, so we've got no way of contacting anyone to see how long it's going to be out or when it will be back on," he said.

Kitchener-Wilmot Hydro said 4,500 customers lost power at some point on Sunday, but it was mostly restored by that afternoon.

However, Hydro One said around 179,000 customers across the province were still dealing with outages by Monday morning.

Winds reached peak speeds of 117 km/h at the Region of Waterloo International Airport on Sunday afternoon.