BOULDER COUNTY, Colo (KDVR) — Wednesday’s fire in Boulder County, called the Table Mountain Fire, was started by a drone crash, according to Sheriff Joe Pelle. 

Three University of Colorado Boulder researchers conducting weather studies were operating a drone in the Table Mountain Radio Quiet Zone, Boulder County officials said. The aircraft crashed at a high rate of speed causing the lithium battery to catch on fire and spread to the surrounding area.

Pelle told FOX31’s Evan Kruegel the drone operators called 911 after crashing the aircraft near the 5000 block of Nelson Road. 

The wildfire quickly grew to about 52 acres, forcing evacuations which have since been rescinded. 

It is not likely that charges will be filed, Pelle said, because the operators weren’t violating any restrictions. 

Pelle says the county is planning to implement fire restrictions Thursday night, or Friday morning.