BOULDER COUNTY, Colo. — The Boulder County Sheriff’s Office has identified the cause of Wednesday's Table Mountain Fire, which forced mandatory evacuations for an area southwest of Longmont.
According to the sheriff's office, three researchers with the University of Colorado Boulder’s Aerospace Engineering Department were at the Table Mountain Radio Quiet Zone and using a drone to study severe weather. At the time, they were flying within regulations. During the study, the drone crashed and hit the ground at a high rate of speed, causing a lithium ion battery cell to dislodge and ignite, the sheriff's office said.
The group used an on-site fire extinguisher but could not stop the fire from growing. High winds caused it to spread quickly.
They stayed at the scene and are cooperating with investigators. The sheriff's office said no criminal charges will be filed.
The fire burned 52 acres. An all-clear was announced around 4:45 p.m.
The National Weather Service in Boulder is warning of “extremely dangerous” fire danger on Friday amid a major weather event to top off a week marked by windy, warm weather and wildfires across Colorado.