The largest wildfire in Texas history, which has killed two people and thousands of cattle across the state's panhandle, was the result of a downed utility pole, a lawsuit filed by a homeowner says.

A cluster of fires broke out last week and quickly spread over several rural counties and into neighboring Oklahoma, fueled by strong wind gusts and unseasonably dry conditions. As of Tuesday morning, the largest of the blazes, the Smokehouse Creek fire, had ripped through more than 1 million acres, destroying hundreds of buildings, evacuating entire towns and burning an area larger than the state of Rhode Island.

On Friday, Melanie McQuiddy, a homeowner in Stinnett, a city where many houses have been destroyed, filed a lawsuit against Xcel Energy Services and two other utilities. The lawsuit says the record-setting fire started "when a wooden pole defendants failed to properly inspect, maintain and replace, splintered and snapped off at its base."

On Feb. 28, two days after the fires broke out, a law firm sent a letter to Xcel notifying the company “of potential exposure for damages” and requesting that a fallen utility pole near "the fire’s potential area of origin be preserved," according to a filing with the U.S. Securities and Exchange Commission.

Kevin Cross, a spokesperson for Xcel, said that the fires are being investigated and that the cause has not been determined. He added that the company restored power in coordination with first responders and local officials.

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

Erin O'Connor, a spokesperson for the Texas A&M Forest Service, said that investigators were working with local law enforcement and that the cause is under investigation. McQuiddy's lawyer did not immediately return USA TODAY's requests for comment early Tuesday.

Fight to contain, put out the fires continues

Authorities expressed optimism in the dayslong fight to quell the flames, and favorable weather conditions were forecast in the coming days.

"Overall, burn conditions are markedly improved from yesterday's weather and the ability to fight fire on the ground is greatly enhanced," an update from the Texas A&M Forest Service said Monday.

Hundreds of local, state and federal personnel as well as U.S. Army troops have been fighting the fires. Dozens of bulldozers have dug out fire lines, and aircraft have dumped thousands of gallons of water and flame retardant on the blazes.

As of Tuesday morning, 15% of the Smokehouse Creek fire had been contained. Stretching across several counties, south of the Smokehouse Creek fire and north of Amarillo, the Windy Deuce fire burned 144,206 acres and was 55% contained as of Tuesday morning. To the east, the Grape Vine Creek fire engulfed 34,882 acres and was 60% contained.

The deaths of two women have been linked to the fires. Cindy Owen was overtaken by flames on Feb. 27 when she got out of her truck in Canadian, a city in Hemphill County where dozens of structures were destroyed, according to the Texas Department of Public Safety. She was taken to a hospital, where she died on Thursday.

The other victim, an 83-year-old woman, was identified by family members as Joyce Blankenship, a former substitute teacher. Her grandson, Lee Quesada, said deputies told his uncle Wednesday that they had found Blankenship's remains in her burned home.

Contributing: The Associated Press