Investigators looking into the cause of a colossal wildfire in Colorado that forced the evacuation of tens of thousands of people are focusing on a property owned by a Christian fundamentalist sect, after witnesses reported seeing a structure on fire there moments before the blaze spread with astonishing speed across drought-stricken suburbs.
Sheriff Joe Pelle of Boulder County said at a news briefing on Monday that the property owned by Twelve Tribes, which was founded in Tennessee in the 1970s, had become a target of the inquiry after investigators ruled out the possibility that downed power lines might have sparked the fire.
Still, Sheriff Pelle warned against jumping to conclusions regarding the fire’s origins, emphasizing that the investigation was in its early stages and that it could take weeks or even months to determine the exact cause. He said investigators from the Federal Bureau of Investigation, the Bureau of Alcohol, Tobacco, Firearms and Explosives, and the U.S. Forest Service were assisting his department’s inquiry.
“We’re going to take our time and be methodical because the stakes are huge,” Sheriff Pelle said.
The efforts to determine what caused the fire are adding to the challenges that authorities are facing in Colorado, after heavy snowfall over the weekend blanketed the suburban areas that had been torched by the Marshall fire. About 35,000 people were forced to evacuate the area last week, and many families remain in shelters after more than 900 homes were destroyed.
Authorities are still searching for two people missing in the blaze, which figured among the most destructive in Colorado history. A severe multiyear drought nurtured the brittle-dry conditions that allowed the fire to sweep through residential areas.
Discussion of the Twelve Tribes property emerged on social media on Thursday, around the time the Marshall fire began spreading, when video of a structure on fire there started circulating. By Sunday, officials confirmed that the fire began on private property at the Boulder County intersection of Marshall Road and Highway 93, which is owned by Twelve Tribes. Sheriff Pelle confirmed on Monday that investigators were examining the site in addition to adjacent areas.
Several witnesses who live nearby said they had alerted the authorities about the fire at the site before hurricane-force winds spread flames around Boulder County. Anne Michaels, a kindergarten teacher who lives in the area, said she was driving by the property on Thursday while talking to her mother on her mobile phone when she noticed something was wrong.
“I said, ‘Mom, I see smoke,’” said Ms. Michaels, 43, adding that the smoke was clearly coming from the Twelve Tribes property. She said she called 911 shortly afterward to alert the authorities.
Mike Zoltowski, another witness who reported seeing the fire on the property, while staying at a friend’s neighboring home, said he saw a fire crew on Thursday unsuccessfully try to put out what appeared to be a shed on fire before leaving the site.
“As soon as I turned around and came back, they were gone,” Mr. Zoltowski told a local television station. “And that’s when I realized something is seriously wrong here, because the shed was still burning.”
A spokeswoman for Twelve Tribes said on Monday that an investigation was taking place but declined to comment further.
Twelve Tribes originated from a youth Bible study group in the 1970s in Chattanooga, Tenn. Since then, it has grown into an international network of self-governing communities scattered across North and South America, Europe and Australia. The settlement in Boulder is one of two in Colorado.
The group promotes itself as an assemblage of up to 3,000 people united by a common belief in God, or Yahshua, and strict adherence to the Old and New Testaments of the Bible, according to its website. Men are expected to wear long beards and tie their hair back, while women dress modestly. Its members often work at several businesses owned by the group across the country, which include a deli in Boulder.
Sheriff Pelle said earlier that a search warrant had been executed as part of the fire investigation, but did not say what location had been searched.
He said that the initial assumptions that downed power lines might have sparked the fire were ruled out after fire investigators and work crews from Xcel Energy, which provides power to the area, determined that the lines in question were used to transmit not electricity but telecommunications data.
In the meantime, the sheriff said investigators were trying to piece together what happened by speaking to as many people as possible. “What I’ve seen today coming in and out of this building meeting with these investigators are dozens of people,” Sheriff Pelle said at the briefing.
He said investigators were “essentially working by hand and with small tools to try to get through those locations” to try to ascertain the origin of the blaze.
“It is very, very difficult work given the debris, the heat,” he said, describing the investigation as “in full force and in full swing.”
Evacuees were waiting for answers. Forrest Smith, 67, who escaped from his home with the clothes on his back, a coffee mug and his smartphone, said he welcomed the investigation into the blaze. But Mr. Smith, who was staying at a Red Cross shelter after the fire gutted his home, expressed doubt that the investigation would result in holding anyone accountable.
“First of all, they’ve got to prove who did it,” said Mr. Smith, a retired truck driver. In any event, he said: “You can’t take it back. What’s done is done.”
Charlie Brennan contributed reporting.