Gusts of up to 100 km/h swept through the area late in the evening, blowing down trees and cutting power.
"I was on a trip to Kelowna. When I arrived back here last night, I just missed the storm but I saw the damage as I came in along the highway," said Brian Taylor, the Mayor of Grand Forks, one of the hardest hit communities.
"I know from reports … cars have been damaged, motor homes have been damaged, trees all around town have fallen down."
The storm also snapped trees at a bible camp in a rural area north of Grand Forks. Two trees fell on a hut, crushing and killing an 11-year-old boy. His name has not been released, but police say he was from Christina Lake.
Others in the hut suffered minor injuries and were treated at the scene by paramedics.
One woman told CBC News she was at a gas station in Grand Forks when the storm hit.
"There’s a lot of debris right here on the main highway going through Grand Forks … there’s big branches down."
As of noon Saturday, more than 13,000 customers remained without power. BC Hydro says crews are working to restore the outages.