The massive wildfire was 10 percent contained after erupting Monday evening near Thomas Aquinas College and subsequently destroying at least 401 structures, fire officials said. Eighty-one other structures have been damaged.
Santa Ana winds propelled the flames to spread quickly toward Ojai, Lake Casitas and the Santa Barbara County line, as well as the Los Padres National Forest.
Some 88,000 residents are still under mandatory evacuation orders as the blaze enters its fifth day and threatens 15,000 structures. Affected communities include Santa Paula, Ojai, La Conchita, Santa Barbara and Carpinteria.
Voluntary evacuation orders were issued for Fillmore and parts of the unincorporated Ojai Valley.
More than 3,200 firefighters from 471 engine companies have been assigned to the incident, which has charred about 206 square miles. Twelve helicopters and seven fixed-wing air tankers, including a DC-10, have been performing water drops on the stubborn flames.
While winds were relatively calm Friday morning in the Fillmore area, terrain-driven flames flared up before dawn and a red-flag warning remained in effect.
At a community center that was serving as an evacuation shelter in Santa Paula, Red Cross volunteer Randy Hitchcock arrived all the way from Sioux City, Iowa, to help displaced residents.
"It's just a phenomenal outpouring from the community and what they're doing," Hitchcock said. "It's great to be here to help them out. That's what our mission is."
No fatalities have been reported in the Thomas Fire, whose cause is under investigation.