Governor declares state of emergency amid stubborn Northern California wildfire

(PHOTO: California Department of Forestry and Fire Protection. 

Gov. Jerry Brown declared a state of emergency Friday for Butte County amid a wildfire that has destroyed 20 homes, scorched nearly 6 square miles and forced residents to evacuate. 

The fire, which is burning near the Northern California town of Oroville, is threatening 500 homes and another 800 outbuildings.

More than 1,600 firefighters are fighting the blaze, and the world's largest and newest aerial firefighting tanker dropped 17,000 gallons of fire retardant Wednesday, marking its first use in the United States.

The fire was 30 percent contained Friday.