Northwest Territories Power Corporation crews have been cleaning up the site where a military helicopter severed power lines to Yellowknife and surrounding communities on Monday.

Line crews are being ferried in and out by air to the site, clearing wires from a trail frequented by trappers and snowmobilers.

Aaron Martin, manager of mechanical services with the NWT Power Corporation says the downed wires have been pulled off the snowmobile trail where they landed after a military helicopter struck them Monday night.   Aaron Martin, manager of mechanical services with the NWT Power Corporation says the downed wires have been pulled off the snowmobile trail where they landed after a military helicopter struck them Monday night. (CBC)

Aaron Martin, manager of mechanical services with the power corporation, said the company was told Monday night the helicopter had come into contact with the power transmission line but was not able to assess the damage until the next day.

"We sent a line crew out here on a helicopter patrol and they informed me the lines were actually on the ground," he said. "The helicopter had flown through and contacted all three phases and tore them down.

"When I got out here, the wire was still laying off the towers in the middle of the Ski-Doo trail that's here, and for safety purposes we instructed the boys to pull the cables off the Ski-Doo trails and get it out of the way,” said Martin.

The cables, more than an inch in diameter, were de-energized the moment the military helicopter hit the lines. They're also now grounded.

The three broken cables carried hydroelectric power from the Snare Dam. Yellowknife and Behchoko are running on diesel-generated power and some hydro from the Bluefish Dam.

The power corporation is waiting on a specialized crew from Grand Prairie, Alta., and three 500 metre lengths of replacement cable to begin the fix.

But the question of who will pay for the repair and the higher cost of diesel power remains up in the air.

The Department of National Defence will investigate the helicopter mishap, and Joint Task Force North said that will determine whether the Canadian Forces is liable for the damages.

It says it has explained to the power corporation how to go about making a claim against the military.

In the meantime, the power corporation says its first priority is getting the power supply back on line, which it expects to happen late next week.