Smoke from a huge wildfire in eastern Arizona has forced nearly 10,000 people to flee their homes as officials warn about serious health impacts to residents and firefighters as tiny particles of soot in the air reach "astronomical" levels.
Calmer winds helped firefighters gain some ground today, but also concentrated the sooty air, keeping it stagnant and raising pollution to levels not yet seen since the blaze began several weeks ago.
Officials plan to bring in more air quality monitoring equipment over the weekend, and have warned people to just stay away.
The fire is expected to move into New Mexico later today, pushed by stronger winds, threatening more towns and possibly endangering two major power lines that bring electricity from Arizona to West Texas.
The fire has burned 639 square miles of forest, an increase of 114 square miles from a day earlier, officials said.
"It's getting very, very close to the New Mexico state line," Jim Whittington, spokesman for the teams battling the fire. "This is really rugged country. There is a lot of potential" for the fire to grow.
He said that after a good day with calm winds yesterday, stronger winds are expected later in the day today.
"The atmosphere will be unstable and very conducive to fire growth," Mr Whittington said. "We're very concerned about the winds."
He said firefighters may eventually have to set ablaze 150,000 acres to burn off fuel in the forest in order to stamp out the flames.
Lighter winds on Thursday and Friday helped the 4,400 firefighters make progress, but critical fire conditions remain.
Fire crews plan to try to strengthen what lines they've been able to establish and continue burning out forested areas in front of the main fire to try to stop its advance.
Nearly 10,000 people have been evacuated from the towns of Sprinerville and Eagar and from several mountain communities in the forest.
The fire is the second-largest in state history and could eclipse a 2002 blaze, known as the Rodeo-Chediski fire, in size, although only a fraction of the homes have burned as yet.
The Chediski began as a signal fire and merged with the Rodeo, which was intentionally set by a firefighter who needed work. Together they burned 1,895 sq. kilometers and destroyed 491 buildings.
The current Wallow Fire in the Apache-Sitgreaves National Forest has destroyed 31 homes or cabins, including 22 in the picturesque mountain community of Greer, Whittington said. Two dozen outbuildings and a truck also were lost and five homes damaged in Greer when the fire moved in Wednesday night.
Firefighters are battling another major wildfire in far southeastern Arizona, also near the New Mexico line. The so-called Horseshoe Two blaze burned through 211 square miles or 135,000 acres of brush and timber since it started in early May. The fire has destroyed 23 structures but caused no serious injuries.
AP