Hundreds of people in a Vancouver suburb watched from their rooftops as a wildfire broke through fire retardant barriers and raged through an immense and environmentally sensitive bog.
Others around the Lower Mainland breathed in a blue, smoky haze yesterday morning and dusted ash from their cars, parked more than 20 kilometres away from the blaze.
The fire, which doubled in size to 20 hectares on Sunday night, tunnelled under fire barriers through veins of peat that snake through the normally wet Burns Bog in Delta, B.C.
The fire's size didn't change yesterday, but the blaze was still out of control despite water bombers, 40 firefighters and flooding of the area by opening floodgates that control the water level, said Delta Fire Chief Gordon Freeborn.
Flames leaped from treetop to treetop, but the fire is difficult to battle because it burns underground through flammable peat moss, he said.
As it burns invisibly, the ground becomes unstable and presents a serious hazard to firefighters, Mr. Freeborn said. And that smouldering peat moss could reignite the vegetation above, he added.
"We're advancing, but I wouldn't say it's under control. Access is a huge problem. It could last a couple weeks until we consider it extinguished.
"A bog fire of this size is never a quick out. It's a long grind."
The fire grew quickly because it started late Sunday afternoon and firefighters ran out of daylight. But firefighters say they extinguished as much as 80 per cent of the above-ground blaze yesterday.
Delta City Councillor Scott Hamilton, whose house borders the area, said he could see the blaze from where he sat.
"I can see a solid column of grey smoke," he said.
"It looks nasty. They don't have a hold on it yet."
Opening floodgates pushes water into the bog, but only near the gates themselves, and the move could flood some local businesses, Mr. Hamilton said.
Delta Mayor Lois Jackson said it isn't the first time the bog has burned. In 1999, a fire at a landfill took nearly two months to extinguish, and an enormous fire in 1996 that was started by a cigarette destroyed 70 hectares of trees.
"We usually get one fire a year, and some are small, some are big -- this is a big one," she said.
Hans Schreier, a University of British Columbia professor who studies soils, said the bog caught fire early in the Second World War, when its peat was mined for magnesium for use in artillery shells. That fire lasted nearly four years, he said.
The largest domed peat bog in North America, Burns Bog stretches more than 4,000 hectares -- 10 times the size of Vancouver's Stanley Park.
Covering the wet ground are trees and bog plants such as sphagnum moss and Labrador tea.
In 2004, several levels of government bought it for $73-million to preserve it.
Eliza Olson, the president of the Burns Bog Preservation Society, said she wasn't concerned about the endangered wildlife inside the bog because fire is a natural part of the bog's lifecycle.
"There were people lined up along the roads . . . and standing on their roofs watching it last night," she said. "It was quite spectacular as the sun went down.
"If the winds are right, the smoke will go all the way up to Howe Sound."
Victoria Ulrich, who ferries travellers from the Lower Mainland to the airport, said she could see heavy smoke and water bombers yesterday morning, and the smoke got worse the farther west she got.
"In Richmond, I was choking because I have bronchial asthma," she said. "You can hardly breathe."
There was a "light dusting" of ash on planes at Vancouver International Airport, said spokeswoman Artie Chumpol, but the smoke didn't affect the airport's schedule.
And while buildings in downtown Vancouver remained surrounded by smoke, no patients in area hospitals have complained, said Fraser Health spokesman Don MacLachlan.
People with respiratory problems should reduce their activity and stay inside until the smoke dissipates, he said.
The cause of the fire is still under investigation, said Chief Freeborn of Delta's fire department.