PITKIN COUNTY, Colo. (CBS4) – Authorities are investigating after vandals targeted the Black Hills Energy system, leaving about 3,500 customers in the Aspen area without heat on Monday. A multi-jurisdictional investigation is underway with the Pitkin County Sheriff’s Office, Aspen Police Department and other agencies.

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“This incident has occurred at a time when so many are trying to enjoy the holidays. It’s absolutely the last thing that any of us would want to occur,” said Aspen Police Chief Richard Pryor during a community meeting on Monday night.

Investigators released a photo to the Aspen Daily News from one of the crime scenes with “Earth First!” scrawled in black marker. The radical environmental group by the same name has not claimed responsibility for the vandalism, according to the Aspen Police Department.

(credit: City of Aspen)

Similar graffiti was found at another scene, according to Aspen assistant police chief Bill Linn. He said the vandalism is considered a felony offense.

More than 100 Black Hills Energy technicians are individually turning off, purging and pressure testing 3,500 gas meters in the Aspen area to bring natural gas customers back online. Customers may smell a faint natural gas due to the controlled release, but officials said this is normal and expected.

Crews plan to relight gas to homes starting late Monday night. The work will continue into the early morning hours on Tuesday.

(credit Black Hills Energy)

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“We’ve brought contractors and our employees in from a multi-state area,” said Vance Crocker, Vice President of Operations for Black Hills Energy Colorado. “We are working safely and as expeditiously as we can to make sure we can get that service back to you all.”

Black Hills Energy requires someone over 18 years of age be present during the relighting process. Crocker said customers can help expedite the process by clearing snow to help crews access gas meters.

If no one is home, technicians will leave a door tag with information to schedule a time to restore service. Customers are asked to not relight appliances on their own due to potential dangers.

(credit: City of Aspen)

Pitkin County officials are working to distribute 4,000 heaters to members of the community. They are available at the Aspen police and fire departments with a limit of one per household.

“I would ask each person in Aspen to check on a neighbor,” said Pitkin County Sheriff Joe DiSalvo. “If you know somebody who may chronically need help or homebound please reach out to those people tonight and see if they’re ok. Hopefully tomorrow we’ll be out of this.”

Customers can call Black Hills Energy at 888-890-5554 if they experience any natural gas service issues or for any non-emergency questions. For more information about the outage, visit the company’s website.

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Anyone with information about the vandalism is asked to call the Aspen Police Department at 970-920-5400.