Rodents gnawing on wires in an electrical box caused a brush fire in Colorado, firefighters said.

Fire crews responded to a fire call in Waterton Canyon early Wednesday morning, Sept. 21, West Metro Fire Rescue said on Facebook.

The rodents “shorted out the system, causing arcing and sparking, igniting the dry grass,” according to a Facebook post.

The fire, which did not threaten any buildings, burned half an acre of hillside “near Strontium Springs Dam,” fire officials said.

Firefighters dug a “perimeter fire line” and also built a “hydraulic to access the water slope,” officials said.

Overnight humidity helped crews slow the fire, according to a Facebook post.

“Now crews are working on hot spots in the area of ​​the fire,” the report says.

Waterton Canyon is about 45 miles south of Boulder.

Rodents gnawing on wires in an electrical box caused a brush fire in Colorado, firefighters said.

Fire crews responded to a fire call in Waterton Canyon early Wednesday morning, Sept. 21, West Metro Fire Rescue said on Facebook.

The rodents “shorted out the system, causing arcing and sparking, igniting the dry grass,” according to a Facebook post.

The fire, which did not threaten any buildings, burned half an acre of hillside “near Strontium Springs Dam,” fire officials said.

Firefighters dug a “perimeter fire line” and also built a “hydraulic to access the water slope,” officials said.

Overnight humidity helped crews slow the fire, according to a Facebook post.

“Now crews are working on hot spots in the area of ​​the fire,” the report says.

Waterton Canyon is about 45 miles south of Boulder.