Damage from a tornado in west end Ottawa, ON, 22 Sept 2018 (Instagram)
Environment Canada has confirmed two powerful tornadoes ripped through west end Ottawa before touching down again in Gatineau across the Ottawa River.
Officials say dozens were hurt and at least two residents are in hospital with critical injuries.
Tens of thousands were left without power after at least 80 utility poles either snapped or were damaged.
Meteorologists say severe thunderstorms spawned one twister classified as an EF-3 with winds up to 265 km/h while another tornado was an EF-2 with winds up to 220 km/h.
Tornadoes are not uncommon in Southern Ontario but storms of this strength are rare.
Trees uprooted by a tornado damage a home in Waterford, Norfolk County, ON, 13 June 2018 (OPP)
Two tornadoes have been confirmed in Haldimand, Norfolk and Oxford counties as severe thunderstorms rolled through Southwestern Ontario on 13 June.
Environment Canada says a tornado categorized as an EF-2 (Enhanced Fujita Scale 2) with maximum winds of 180 km/h ripped through the communities of Jarvis and Waterford uprooting trees, ripping shingles off buildings and destroying several barns.
Damage was reported intermittently along a path roughly 32 km long.
A second, less powerful twister categorized as an EF-0 struck near the town of Norwich around the same time and caused minimal damage.