VANCOUVER -- The Two Mile Road fire threatening Sicamous, B.C., started after a van hit a hydro pole, knocking it over and causing power lines to spark in dry grass for 100 metres in either direction, according to the town's mayor.

It happened just before 11 a.m. Tuesday, and by evening the blaze had forced a thousand people to flee their homes and left most of the rest of the residents on evacuation alert.

Highway 97A remains closed south of town as fire crews work on the ground and in the air to contain the blaze.

The fire, classified as out of control, had scorched about 60 hectares by nightfall on Tuesday.

According to the B.C. Wildfire Service, by mid-day Wednesday the fire had grown to 400 hectares in size.

Mayor Terry Rysz said the wind was blowing from the north Wednesday morning, pushing the fire away from the town.

"We're trying to establish a barrier at the north end of that fire so it doesn't come our way. Right now, we haven't lost a residence,” he said in an interview with CTV New. “We've been very fortunate. But I tell you what, it was within a hundred metres of our trailer park in that particular area where the fire started."

Rysz said after the van knocked down the power pole, the driver, who was not injured in the crash, remained inside the vehicle to avoid electrocution, and called 911.

“Right away, the B.C. Wildfire Service was contacted. And within 20 minutes, there was three, four or five helicopters all over this fire,” he said.

With concerns the wind could shift and push the blaze back towards the town, the evacuation orders and alerts remain in place for now.

Interior Health has evacuated an assisted living facility in Sicamous and moved some other medical patients to neighbouring communities.

Residents on evacuation alert are encouraged to make arrangements to stay with family and friends because there is limited hotel space available in nearby communities.