California Governor Jerry Brown recently declared a state of emergency in Lake and Napa counties, after a wildfire burned and destroyed homes across a span of more than 60 square miles within 12 hours, ABC News reports.

USA Today reports that at the start of the wildfire, thousands of people fled their homes on Saturday, while four firefighters suffered second degree burns while combating the blaze in Northern California.

California fire spokesperson Daniel Berlant spoke to USA Today, and said that the injured firefighters were airlifted to a local hospital and have been listed in stable condition.

Since the tragic fire began, Gov. Brown has explained that the state of emergency declaration "will expedite debris removal and waive fees to people who need to replace official documents lost in the fire."

The cause of the blaze, dubbed the Valley Fire, is unknown, but officials are currently investigating what sparked the fire.

Prior to the Valley Fire, there was another wildfire that grew rapidly over the course of two days in Amador and Calaveras counties. That wildfire was approximately 15 percent contained on Saturday, while firefighters continued to battle the blaze that forced many residents to flee their homes.

"It's expanding like a balloon," state fire spokeswoman Nancy Longmore told USA Today. "It's moving very fast. There's many homes threatened. ... This fire is extremely dangerous."

California Fire Incident Commander Phill Veneris also addressed the numerous wildfires and warned residents that "if you see smoke or fire approaching your community, evacuate the area immediately to a safe location."

As firefighters actively try to contain the fires, authorities tell ABC News that northern California's "dry conditions, steep terrain and limited access to the flames are making for a challenging firefight."