The main post office in Newfoundland and Labrador was temporarily shut down Friday morning after strong winds tore parts of the roof away from the Kenmount Road building in St. John's.
As a result, mail service was halted in the capital city region.
"We don't have any delivery in St. John's today because we don't have any employees in the building," Canada Post spokeswoman Denise Corra told CBC News.
Craig Dyer, the chief shop steward with the Canadian Union of Postal Workers, said the union is upset that workers, who had reported the problem at 5 a.m. as they arrived for work, were not immediately evacuated from the building.
"We have a huge safety concern. We will be looking for an investigation," Dyer told CBC News.
"Our concern as a union was that it took about an hour to evacuate the building."
But Corra says employees were kept inside until it could be determined that it was safe for them to leave.
Canada Post had an initial assessment of the damage done Friday, but it remained unclear how long repairs would take. "Our immediate priority is to get a contractor in to contain the damage," Corra said.
A large portion of the roof could be seen dangling from the edge of the building. Other parts were scattered around the parking lot.
The Royal Newfoundland Constabulary responded and cordoned off the parking lot.
The blustery weather prompted safety warnings from police. It's also affected transportation around Newfoundland and Labrador.
The Bell Island ferry service was suspended, while Marine Atlantic was hoping to end a two-day shutdown on the Cabot Strait and clear a backlog of traffic between Nova Scotia and southern Newfoundland.
Some arrivals at St. John's International Airport were also delayed overnight.