BOULDER COUNTY, Colo. (KDVR) — One year after the Marshall Fire ripped through parts of Boulder County, one question stands out from the rest: What caused this fire?

FOX31 looked into that question and its possible answer, or answers.

It has been said that “what is done cannot be undone, but one can prevent it happening again.” On Dec. 30, 2021, what was done to Boulder County was nothing short of an “urban hell.”

“The crazy part of the fire was that it burned across U.S. 36, six lanes, and went into the city of Louisville. I would have never expected that,” said Boulder County Sheriff Joe Pelle, who’s set to retire in just a few weeks.

‘Close to having a resolution’ on Marshall Fire investigation

FOX31 pressed the sheriff about when the public will finally learn the cause or causes of Colorado’s most destructive fire.

“I can tell you we have investigated every potential cause, and I think we have it narrowed down to probably a couple of potential causes of ignition,” Pelle said.

The Problem Solvers have looked into at least three potential causes based on viewer videos, tips and – quite frankly – rumors from the community. Those include the fire at the property owned by 12 Tribes, downed Xcel Energy power lines and the Marshall coal mine fires underground.

“We’re looking at all those things,” Pelle said. “I think we’re close to having a resolution.”

The Problem Solvers have learned the Boulder County Sheriff”s Office will be finished with its investigation into the fire by early next year.

Could criminal charges come?

When it’s all said and done, will there be criminal charges filed?

“That’s one of the things that’s being sorted out right now,” Pelle said. “You know, the real cause of that fire was under 100-mph winds and extreme drought, and so what we’re trying to figure out right now is what the ignition points were.”

For now, what’s done cannot be undone. But the hope moving forward is finding what started the fire in order to keep this from happening again.

For its part, Xcel Energy told FOX31 the power lines and equipment in question were thoroughly inspected and showed no signs it started the fire. Officials with 12 Tribes had no comment when FOX31 asked them about the fire seen on their property the day of the Marshall Fire.