• UPDATE at 6 a.m. MT: Yellowknife and Dettah are now back on hydro power. People in Behchoko are still being asked to conserve power. 

A damaged power transmission line to Yellowknife triggered a series of power outages Tuesday afternoon.

A spokesperson for the Northwest Territories Power Corporation says it has not determined whether the damage to a transmission line from the Snare hydro-electric facility was caused by forest fires in the area.

That facility supplies power to Yellowknife and the community of Behchoko, about 100 kilometres northwest of the city.

The spokesperson said the damage occurred to a section of the line that runs to Behchoko. Smoke is preventing crews from assessing and repairing the damage.

The corporation is using diesel-generated power plants to supply electricity to the two communities, but hydro power to Yellowknife is expected to be restored Tuesday evening.

In the meantime, it is asking residents in Yellowknife and Behchoko to conserve power by turning off appliances and unplugging unnecessary electrical devices.

NTPC shut down the Taltson hydroelectric plant for four days earlier this month because a forest fire was approaching its power transmission lines. In June, a raven caused a power outage and a forest fire near the Bluefish hydro plant.

The Snare Lake transmission line was previously damaged in February 2012 by a Canadian Forces helicopter on a training exercise. In that incident, the city ran on backup diesel for 10 days.