CALGARY - Blocks of office towers remain quiet and dark in downtown Calgary due to a power outage that began on the weekend and may not be repaired until at least Thursday.
Mayor Naheed Nenshi has told businesses in the affected zone they should tell employees not to come in to work and to make alternate arrangements.
Thousands of people have no power in their homes since the outage has also affected many downtown apartment buildings.
Provincial courthouses in Calgary will be closed today and Premier Jim Prentice says his own office in the city is dark.
The blackout began late Saturday after a fire in an underground vault which utility company Enmax says requires equipment to be replaced rather than simply repaired.
The cause of the fire is still under investigation.
"Unfortunately many in downtown Calgary have had their Thanksgiving disrupted by circumstances that are beyond their control," Prentice told a news conference on Monday afternoon.
"As we all know thousands are without power and have been evicted from their homes because of the underground electrical fires and they've voluntarily evacuated from their residences."
The Calgary Chamber of Commerce is encouraging employers to avoid having employees come into work, suggesting teleworking or using offsite locations as alternatives.
It says buildings in the affected area will not have light, power, phones or Internet, which may create safety risks.
Calgary's light rail C-Train, which passes through the affected zone, suspended service through the area on Saturday night when police roadblocks prevented access. But service resumed Sunday when the roadblocks were removed and the system continues to operate normally.
The city warns that water pressure may be weak or non-existent in buildings above the fifth floor.
It says it will allow the deployment of industrial generators at street level, but it says building owners must still get permits.