Three months after the state’s most destructive fire destroyed nearly 1,100 homes in Boulder County, authorities announced on Thursday that the investigation is ongoing and expected to take “several more months.”

The Boulder County Sheriff’s Office said it’s been working with experts from across the United States to thoroughly analyze evidence and identify the possible cause and origin of the Marshall fire. 

To date, investigators have followed up on nearly 200 tips from residents, executed search warrants for physical and digital evidence, reviewed hundreds of videos and photos, interviewed hundreds of victims and witnesses, and reviewed “countless” 911 calls, according to the Sheriff’s Office.

Marshall Fire: Full Coverage

“The Sheriff’s Office recognizes the importance of this investigation and the community’s desire to understand what happened, however, we believe a thorough investigation is always warranted,” officials wrote in a news release.

The lack of any conclusions by investigators didn’t prevent a class action lawsuit from being filed.

Denver Gazette partner 9News reports that the suit, filed Thursday, accuses Xcel Energy of negligence, claiming power lines and utility equipment “were a substantial factor in the cause, origin, and continuation” of the wildfire.

Documents list the plaintiffs as two businesses and John and Jane Doe, a married couple characterized as “terrorized and damaged” by the fire that tore through parts of Boulder County on Dec. 30.

This couple, the lawsuit says, filed the lawsuit on behalf of Coloradans who experienced property damage or suffered financial loss because of the fire.

The lawsuit contends that just before the fire, a witness captured video showing sparks flying from a malfunctioning power line near the Shell gas station at 1805 South Foothills Highway, in the Eldorado Springs neighborhood of Boulder County.

The lawsuit claims these sparks ignited the Marshall fire.

According to the lawsuit, the design of Xcel’s infrastructure presents “inherent danger.” The plaintiffs accuse the company of failing to properly inspect and maintain power lines.

Once the investigation is finished, investigators will present the evidence to the Boulder County District Attorney’s Office, which will determine whether to file charges. 

9News contributed to this report. For more on this and other stories visit our partners at 9New.com