One of the California wildfires grew so fast it burned the equivalent of a football field every second

The three main wildfires raging in California have expanded rapidly, devouring virtually everything in their paths.

One fire burned an area equivalent to the size of a football field every second from Thursday into Friday.

Intense winds and low humidity are feeding the flames. So is dry vegetation, as much of California has seen less than 5% of its normal rainfall over the last month.

Here are some other startling facts about the fires:

CAMP FIRE

The Camp Fire, which is burning in Butte County in Northern California, had grown to 100,000 acres on Saturday.

It had charred 20,000 acres Thursday in less than 14 hours.

It grew by 5,000 acres Thursday in just three hours, according to Cal Fire, meaning it expanded by an average of more than one football field every 3 seconds during that period.

The Camp Fire's most significant growth period was early Thursday afternoon, when it grew 10,000 acres in about 90 minutes -- burning the equivalent of more than one football field every second during that time.

The fire has claimed nine lives in Paradise, according to the Butte County Sheriff's department.

It has also destroyed an estimated 6,700 structures, an incident report by Cal Fire said.

WOOLSEY AND HILL FIRES

The Woolsey Fire, which is threatening parts of Ventura and Los Angeles counties, grew to 8,000 acres in about 13 hours from Thursday afternoon into early Friday morning. By Saturday, it was at 70,000 acres.

In 90 minutes Friday morning, the Woolsey fire doubled in size to 8,000 acres. That's 44 acres burned a minute, or about a football field every two seconds.

The Woolsey Fire is one of two blazes burning just miles from the site of Wednesday night's mass shooting in Thousand Oaks. This one is just to the east of that city, part of which was evacuated.

The other fire in that area is the Hill Fire, which torched 10,000 acres in six hours on Thursday.

Just 12 minutes after it started Thursday afternoon, the flames spread across US 101, leaving several drivers temporarily stranded.