Tornado – 1974
On April 3, 1974 a F3 class tornado ripped through Windsor after crossing the Detroit River. It was one of 148 confirmed tornados to touch down in North America on that day. 
The 1974 tornado in Windsor is listed as the 6th deadliest tornado in Canadian history, killing 9 people and injuring dozens more.
The tornado first struck the south part of the Devonshire mall before moving to the Windsor Curling Club on Central Avenue. The tornado ripped the roof off the building, and a concrete wall collapsed. 8 people were killed, with one succumbing to his injuries 9 months later. Much of the rescue efforts were carried out in the dark.
The tornado was reported to have a width of more than 300 meters. Although the tornado hit the Curling Club at 8:09 pm, the tornado warning for the Windsor area, issued by the Canadian Weather Service was issued at 8:15 pm.
Sources:
Complete History of Tornadoes in Windsor and Essex County.
It Could Happen Here: Remembering Deadly Windsor Tornadoes.
Survivors Still Haunted by Deadly Tornado that Destroyed Windsor Curling Club.
Warning Phase Activities of the 1974 Windsor Tornado.