Hurricane Fiona made landfall in eastern Canada on Saturday after sweeping past Bermuda.
The storm brought heavy rainfall with maximum winds of 90 miles (144 kilometers) per hour. Some areas recorded rainfall of up to 4.9 inches (125 millimeters).
The province of Nova Scotia was on high alert, with the Atlantic Canada region preparing for what forecasters warn could become one of the most severe storms in the country's history.
"It is certainly going to be a historic, extreme event for Eastern Canada," Bob Robichaud, a meteorologist for the Canadian Hurricane Center, told the media.
"It's a major hurricane ... All that momentum is trapped within the storm, so it's very difficult for something like that to actually wind down."
Fiona transformed from a hurricane into a post-tropical storm late on Friday.
However, experts said that it could still have hurricane-strength winds and would bring lashing rains and huge waves.
Trudeau: 'It's going to be a bad one'
Prime Minister Justin Trudeau delayed his Saturday departure for Japan, where he was to attend the state funeral for assassinated former Prime Minister Shinzo Abe.
"It's going to be a bad one,'' he said on Friday.
"We of course hope there won't be much needed, but we feel there probably will be," Trudeau said. "Listen to the instructions of local authorities and hang in there for the next 24 hours.''
Over 250,000 Nova Scotia Power customers were affected by outages just after 1 a.m. local time (0400 UTC).
The numbers spiked by another 28,000 by the end of the hour.
Authorities in the province sent an emergency alert to phones warning of Fiona's arrival and asked people to stay indoors, avoid the shore, charge devices and have enough supplies for at least 72 hours.
Residents were also warned of wind damage to trees and structures, coastal flooding and possible road washouts.
Two of Canada's biggest carriers — Air Canada and WestJet Airlines — halted regional service from Friday evening.
Several killed in Puerto Rico, one in Guadeloupe
No official reports of serious damage came in when the storm system passed by Bermuda earlier in the day.
Fiona so far has been blamed for the deaths of at least five people, four in Puerto Rico and one in Guadeloupe earlier this week, according to US officials.
US President Joe Biden declared a state of emergency in Puerto Rico, which is still reeling from the destruction caused by Hurricane Maria five years ago.
Meanwhile, in the Dominican Republic, President Luis Abinader declared three eastern provinces to be disaster zones.