FIRTH — The Lavaside fire near Firth which started Wednesday afternoon gained strength and acreage quickly Thursday afternoon, pushed along by winds from the south, and several houses on a Bingham County road were evacuated Thursday afternoon.

The fire was estimated to be 500 acres in size as of 4:30 p.m. on April 22.

Around 2 p.m. Thursday, Bingham County sheriff’s deputies began evacuating approximately 15 homes on 700 North in the area of the wildfire that had been burning west of Firth since late Wednesday afternoon.

The resurgent wildfire was burning toward 700 North, and sheriff’s deputies closed the road to all traffic.

Shortly before 5 p.m., the sheriff’s office said one home’s roof had caught fire and firefighters were actively working to extinguish the flames.

The wildfire turned the tables on firefighters after authorities had said Thursday morning that 25 percent of what was then a 190-acre fire had been contained and full containment was expected by 6 p.m. Thursday.

The wild card was going to be the wind, which picked up enough on Thursday afternoon to cause the fire to resume its spread.

The wildfire was reported on private land about four miles west of Firth at about 4 p.m. Wednesday and had been spreading in thick vegetation including juniper, willow and cottonwood trees along the Snake River.

Early Wednesday evening the flames were towering higher than the trees in their path and smoke from the blaze could be seen from over 20 miles away.

The blaze that began as a controlled burn sent enough smoke and ash to the south that the state Department of Environmental Quality’s Pocatello air monitoring equipment showed as of Wednesday night that the air quality in the Pocatello and Chubbuck area had decreased from good to moderate, meaning that people sensitive to air pollution could have suffered negative health impacts.

As of 10:30 a.m. Thursday, however, the air quality in Pocatello and Chubbuck had rebounded back to healthy levels.

Bingham County Sheriff Craig Rowland said the controlled burn was started by someone burning a ditch or weeds but the flames got out of control.

On Wednesday night, the flames did burn to within a half-mile of homes, but authorities reported on Thursday morning that those structures were no longer threatened.

That obviously changed on Thursday afternoon when the winds picked up and pushed the flames forward.

Firefighters from Firth, Blackfoot, the Bureau of Land Management, U.S. Forest Service and Bureau of Indian Affairs were aggressively battling the fire and working to protect structures in the area.

The wildfire burning near Firth, a town of about 525 people located northeast of Blackfoot, is the latest of several recent East Idaho blazes caused by controlled burns that got out of control.

Kelsey Griffee with the Bureau of Land Management said winds will remain a concern over the next couple of days and conditions are incredibly dry right now. It’s also early in the fire season so federal crews have smaller staffs than usual and the firefighters that are available are tied up on existing fires.

She urges people to be extra cautious right now.

“It’s not a good time for debris burning or any sort of spring cleaning (that involves) debris burning,” Griffee said.