The cause of this morning's systemwide power blackout is still under investigation, says Yukon Energy spokesman Janet Patterson.

Patterson said the outage occurred shortly after 8 a.m. during routine maintenance on turbine number four at the Whitehorse Rapids Dam.

Staff did what they always do, but for some reason, the territory's largest hydro generator didn't like it, she explained.

"They are doing an investigation to find out more about why it happened as it did.”

All 14,000-plus customers across the entire Whitehorse-Aishihik-Faro grid were without power for anywhere from 20 minutes to almost an hour.

Patterson said Riverdale was the first to come back on at 8:26 a.m., all of downtown was restored by 8:37 a.m., and the remainder of the customers came back on a little at a time, though the entire grid was fully charged by 9:06 a.m.