This is an archived article that was published on sltrib.com in 2017, and information in the article may be outdated. It is provided only for personal research purposes and may not be reprinted.
Fire investigators determined that a hot 50-caliber bullet casing caused a 392-acre wildfire in Utah County, and crews made progress hemming in the blaze Monday.
About 40 firefighters from local, state and federal agencies were working Monday night to extinguish the Water Tower Fire, which was about 60 percent contained, said Shayne Ward, fire information officer. Earlier in the day, there had been about 100 firefighters on the scene, along with three water-bearing helicopters in the air, but the aircrafts were deemed unnecessary by late afternoon.
The fire broke out near a water tower about a mile northeast of Alpine at 8:12 p.m. on Saturday after target shooters fired a 50-caliber bullet that landed on the dry ground.
A bullet like that has enough energy to travel several thousand feet per second, said Ward, and that energy has almost a "molten" effect on the casing. The heat from that bullet's energy — rather than a spark from it colliding with something — ignited the fire, he said.
The area where the fire began is on public land, where target shooting is legal, according to Ward. Many shooters practice in the area and leave behind litter, including items used for target practice, like refrigerators and televisions, he said.
The fire has burned mostly grass and bushes, though there was "a little bit" of timber that had also been charred, Ward said.
"It's almost 100 degrees out here. The relative humidity is low," Ward said. "Any heat source" has the potential for starting a fire.
"No one is setting fires intentionally in this area," he added, but he asked that the public be aware of the conditions before engaging in an activity that could result in a fire.
"There's a time and place for everything," he said.
On Sunday morning, residents of about two-dozen homes near the wildfire were evacuated as a precaution, but they were allowed to return home after the evacuations later that day. No one has been reported injured and no structures were being threatened as of Monday night.
Trails running through the burned area were closed, fire officials said.
With perimeters increasingly secured, the flames were moving uphill and away from residential areas toward a Uinta-Wasatch-Cache National Forest wilderness area.
Ward said crews planned to focus on using natural terrain and construction of new lines and breaks to contain the fire.
Otherwise, the blaze will be allowed to burn itself out within its interior, which Ward described as dangerous steep and rugged country for firefighters. The fire has cost about $450,000 to fight.
Twitter: @remims, @mnoblenews
Editor's note: Due to an erroneous news release, the cost of fighting the fire was misstated in an earlier version of this story.