BOULDER COUNTY, Colo. (CBS4) – Firefighters battled a fully-engulfed house fire in the 2000 block of Lefthand Canyon Drive early Thursday morning.

(credit: CBS)

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The Boulder County Sheriff’s Office says neighbors in the area called 911 to report a possible structure fire. Crews arrived to find smoke and flames coming from the three-story wooden home.

No one was inside the home at the time.

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(credit: Boulder County)

The fire was so intense that firefighters were not able to get into the building. One vehicle was seen in the garage.

Several agencies responded to this fire, including the Boulder County Sheriff’s Office, Lefthand Fire, Hygiene Fire, Lyons Fire, Boulder Mountain Fire, Boulder Rural Fire, Jamestown Fire, Boulder Emergency Squad, Longmont Emergency Unit and the Red Cross.

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Investigators are working to figure out how the fire started.