Transcript for More Than 13,000 People Evacuated as Wildfires Grow in California
We have it with Clayton Sandell on the front lines. Reporter: Tonight, the 100-square-mile rocky fire is threatening nearly 7,000 homes. Over the past several days, what we have seen is explosive fire behavior. Reporter: Yesterday, the fire jumped this highway, starting a spot fire that was 3200 acres. It's not as hot today. But the moisture, can bring lightning and downdrafts to make a fire unpredictable. The firefighters tell us when you sometimes see a fire tornado, a fire whirl as they call it, that means the air here is extremely unstable. Watch from above. The fire appears to go out and win the wind changes suddenly, the fire changes direction again. There is a thick layer of ash on the ground and it smells like a charcoal grill. But this tree appears to have stopped burning. But if you come down here to the roots under ground, it's still burning hot. It can go on for hours, or days longer and it can of course lead to flayups. Stopping those flare ups, now up to 3,200 firefighters and a fleet of helicopters and planes, including military tankers, protecting the homes of 13,000 evacuees. This is the first time that I'm really feeling afraid that I could lose my house. Reporter: And thanks to the fire, schools here will start a week late. And, David, this is the area where those 24 homes were lost you can see some of the devastation left behind and with thousands more threatened, firefighters are working desperately to make sure no one else loses their home, David? All right, sir, Clayton
This transcript has been automatically generated and may not be 100% accurate.