A video filmed by a sheriff's deputy in Sonoma County, California, illustrated the intensity of the so-called Tubbs Fire, as its flames spread from Napa to Sonoma County.

The video was posted to Facebook Wednesday morning, along with a warning that neighbors should stay safe and look out for each other.

"As both the Sheriff's Office and a County Agency full of Sonoma County residents, we are proud of all who have risked harm to help each other out in times of peril," the Sonoma County Sheriff's Office wrote in the post. "This is but one moment in a series of moments that will end up defining the strength of our Community through what will be a pinnacle moment in Sonoma County history."

The Tubbs Fire has destroyed hundreds of homes over at least 28,000 acres of Northern California, where at least 17 people had already been killed in fires, as of Wednesday morning.

NBC News contributed to this report.