Xcel Energy's stock fell nearly 9% on Thursday after the company said it was notified its equipment could be responsible for sparking a wildland fire in the Texas Panhandle that has grown to be the largest in that state's history.

The Minneapolis-based company said in a filing with the Securities and Exchange Commission that it received a letter Wednesday from a law firm representing property insurers aiming to notify Xcel had it "potential exposure for damages" from the Smokehouse Creek fire.

The letter asked Xcel to preserve a fallen utility pole in the area the fire potentially started.

The Smokehouse Creek fire is 3% contained, according to a report on the federal fire monitoring website InciWeb. The cause of the fire is still under investigation.

However, as of Thursday morning, the Smokehouse Creek fire in Hutchinson County had merged with other fires, creating "the largest and most destructive" blaze in Texas history, so far burning more than 1 million acres, according to the Texas A&M Forest Service.

Officials said snow fell on large portions of the fire Thursday morning and the fire had moderate potential for growth because ground crews were making slow progress with heavy equipment because of rough terrain. The fire is mostly burning in tall and short grass, as well as timber in the bottom of canyons.

Xcel spokesman Theo Keith said in a statement that the company will cooperate with officials while also conducting its own investigations to determine the causes of the fires.

"Our thoughts are with the families and communities impacted by the devastating wildfires across the Texas Panhandle," he said. "As members of this community, we will continue to support our neighbors in this recovery."

The East Amarillo Complex fire in 2006, now the second-largest in Texas, burned about 907,000 acres, according to historical data.

"This is now both the largest and most destructive fire in Texas history," the West Odessa Volunteer Fire Department said in a Facebook post.

Charles Clark, a volunteer firefighter, was responding to calls as his home in Stinnett was burning.

"My house was already burning, and there were houses that could be saved," he said. "That's part of being a volunteer and taking care of your community."

His house was located in the Scotts Acres neighborhood, one of the worst impacted areas of the city where an 83-year-old woman was confirmed to have died in the fire. As of early Thursday afternoon she was the only reported death.

Xcel continues to face legal challenges over the December 2021 Marshall fire near Boulder, Colo., that claim the company is partly responsible for the destructive blaze. Xcel denies it is at fault and claims the sheriff's investigation that concluded its equipment caused one of two blazes that merged is flawed.

However, in January, Xcel said in its quarterly earnings report that if the company was found liable and required to pay damages, the amount could exceed its insurance coverage of roughly $500 million and hurt its "financial condition, results of operations or cash flows."

The fire burned over 6,000 acres, killing two people and destroying over 1,000 residential buildings and reportedly causing about $2 billion in property damage.

Xcel's earnings report said the company is aware of 298 legal complaints on behalf of at least 4,047 plaintiffs including local homeowners and Minneapolis-based Target.

Xcel's two major markets are in Colorado and Minnesota, although it covers parts of several other states including Texas.

Last Friday, Southern California Edison agreed to pay $80 million to settle claims on behalf of the U.S. Forest Service connected to the massive Thomas wildfire that destroyed more than a thousand homes and other structures in 2017, federal prosecutors said Monday.

The utility has also settled claims related to the enormous Woolsey fire in 2018. Edison estimated in 2021 that total expected losses for both blazes would exceed $4.5 billion.

Includes reporting by the Associated Press.