A North Dakota businessman visiting the San Diego area saw a black sky filled with ashes, as a result of the Southern California wildfires.

"It's unbelievable," R.D. Knutson, of Fargo, told WDAY radio by phone. "There's inches of soot and ash. It's like being in the plume of a volcano. It's absolutely black."

Knutson said the closest fire was miles away, but strong winds were blowing the smoke and ash directly over San Diego.

"Obviously, it's just a terrible situation down here," he said.

Authorities reported six major fires and several smaller ones stretching from the Mexican border to the suburbs north of Los Angeles. At least 13 people were killed, and more than 825 homes were destroyed.