One year later, still no official cause of Marshall fire

What the Marshall fire destroyed is not in dispute, more than 1000 structures, how it began is still the unanswered question. Downed power lines were quickly blamed, but then retracted by the sheriff's department.

Nevertheless attorney James Avery filed a lawsuit against Xcel Energy claiming they believe the fire was started by the lines.

"We have our own investigators and we have our own theory on cause," he told CBS News Colorado.

Video from the day of the fire, taken by Edward Harrell, showed utility lines arcing In the high winds.

Avery explained, "Like where there's smoke there's fire same thing with powerlines you have that smoke that shows damage to the powerlines and shows that."

"There was molten metal that was likely cast into the 100 mph winds blowing directly onto the open space field," Avery said. 

Xcel responded in a statement saying, "We have conducted our own investigation into the cause of the Marshall fire, and based on that review, we do not believe the fire was caused by our equipment or operations."

People in the area who we met say they'd like to learn the cause including Roger Funk who was nearby that day.

"For me it was how the fire could just come out of the foothills and take out entire neighborhoods to actually see it happen was just shocking," he said.

The Boulder County Sheriff's Office spokesperson, Carrie Haverfield, emailed CBS News Colorado stating, "We are still waiting on some outside review/assistance. I truly hope we will have an update soon."

Other possible sites of the fire ignition being examined have included property of a religious group, which had no comment today and an old underground coal mine fire.

Regarding the lawsuit, Xcel added, "While we had hoped the case would be dismissed at this early stage in the proceeding, we are prepared to vigorously defend against this lawsuit and believe we will be successful."