It's been nearly 30 years since a powerful tornado ripped through the Barrie, Ont., area, killing 11 people and leaving a wide path of destruction, but the memories of the natural disaster are still fresh in the minds of many residents.

Carol MacMillan was mowing her lawn on May 31, 1985 when she noticed a sudden change in the air, alerting her to the fast-approaching twister.

"The sky was green," MacMillan recalled. "You could feel it was almost an electrical static in the air."

Barrie tornado

Barrie tornado

The north-east travelling tornado ended up missing MacMillan's home and instead moved down into a valley, obliterating other buildings in its path, including Natalie and Verne Ferrier's house. The pair was standing in their garage with two friends when the tornado struck.

"We didn't see it coming because it was behind us," Natalie Ferrier told CTV Toronto on Friday.

Barrie tornado

The tornado blew away the garage and uprooted trees that could be seen flying over top of them. A number of branches landed on Ferrier, and her husband was struck by a piece of farming equipment.

"I was laying under a bunch of trees so they had to lift them off and (my husband) got hit by a plow," Ferrier said.

Barrie tornado

The tornado then travelled east over Highway 400, carving out a path of destruction approximately 600 metres wide. A home where a 12-year-old girl and her grandmother were staying at the time was on that path. The girl helped saved her grandmother by leading them to a basement storm cellar.

"She took them into these doors and this is where they stayed," said Linda Marek, who now lives in the home. "When they opened the doors, they could see the sky."

In total, 13 tornadoes touched down in Ontario that day, killing 11 people -- eight in Barrie and three in the nearby community of Grand Valley. Across North America, dozens of twisters also struck Ohio, Pennsylvania, and New York, making the disaster one of the most intense tornado outbreaks to hit the region in history.

Barrie twister

Barrie tornado

The fatal Barrie twister was rated an F4 on the tornado scale, as violent winds on that day topped more than 330 kilometres an hour.

Technology in those days meant that residents only had minutes to run to safety, but today, that warning time has increased to 15 minutes and experts predict that will likely increase in the future.

"Are we eventually going to see 15 to 30 minutes, 30 to 40 minutes? I think it's going to happen but it's difficult to say what that timeline is going to be," Environment Canada meteorologist Geoff Coulson said.

Records show the 1985 Barrie tornado is still considered the strongest one to ever touch down in Ontario. Experts say storms of that magnitude typically come around every 15 years.

With a report from CTV Toronto's Zuraidah Alman