GOLETA, CA (AP)  -- Flames and fleeing headlights lit up the early morning Friday as thousands left their threatened homes in the face of an out-of-control wildfire in Santa Barbara County.

The fast-growing fire in the Los Padres National Forest burned one structure and spurred authorities to order the evacuation of about 1,700 homes in several small communities in and around Goleta.

The Gap Fire, one of hundreds burning in California, has burned about 3,000 acres—the equivalent of almost 5 square miles—in the foothills of the Santa Ynez Mountains, county communications director William Boyer said.

He could not immediately provide details on the structure burned.

Mandatory evacuation orders were issued for residents living along several roads west of the San Marcos Pass and in the Hidden Valley, Trout Club and Painted Cave communities.

Some 40,000 Southern California Edison customers lost power for two hours as thick smoke forced the shutdown of electric transmission lines for the second straight night, utility spokeswoman Nancy Williams said. Crews could not turn the power back on right away because a power substation was surrounded by flames.

John Palminteri, a reporter for KEYT-TV, said a long line of cars was streaming down Hollister Avenue, a main thoroughfare in Santa Barbara.

There were "headlights as far as I can see in every direction. Everyone is panicking," he said.

The Red Cross set up an evacuation center at an area high school.

Retired Civil Engineer Jerry Smith, who fled his house with family photos, medicine, paintings made by his sister and his son, said the mood at the center was "resigned but hopeful."

"We're patient. There's not much we can do now."

About 750 firefighters were battling the fire as the region's notorious "Sundowner" winds blew down from the mountains toward the coast. Evening wind gusts were expected to reach 40 mph, County Fire Captain Eli Iskow said.

The fire was moving downhill and northeast toward rolling ranch land and orchards along Highway 154, Boyer said.

The fire's intensity prompted Goleta's Rotary Club to cancel its 34th annual Fourth of July fireworks display.

The city of about 55,000 is 8 miles west of Santa Barbara.

Authorities said the area hadn't burned since 1955 and some of the chaparral stood 20 feet high.

Seesawing winds made it hard on firefighters, Iskow said.

"It's definitely expanded in width; it's taking quite a jump to the east along the mountain ridge ... above populated areas," he said.

Resources were being stretched by the requirements of some 1,000 other fires in the north, Iskow said.

"We are definitely with competition with all the other fires in the state," he said. "Aircraft come off those other fires and fly directly to us."