Smoke from the Thomas Fire, shown last week over the 101 Freeway near Carpinteria, Calif., has created significant concerns about air quality. (Stuart Palley/For The Washington Post)

Casa Dorinda, a majestic 48-acre multiunit retirement community, peers up over a carefully manicured treetop canopy here, its outdoor pool, wooded pathways and full-service private medical center part of an oasis along the Southern California coast.

But with the Thomas Fire burning nearby for a second week, Casa Dorinda was eerily quiet on Friday morning as the region continued to choke on smoke and ash.

“The place is empty,” said one resident, 90-year-old Sam Fordyce. “A lot of people left.”

With fire crews continuing their battle against the fourth-largest wildfire in modern California history, smoke inhalation has become a major concern for residents in Santa Barbara and Ventura counties. Though the skies cleared a bit on Friday, officials warn that erratic Santa Ana winds could make conditions difficult to forecast. It could mean more smoke and the potential for fire in residential areas.

Authorities said Thursday that a firefighter died during the response to the Thomas Fire, the second casualty linked to the blaze.

Authorities identified the man as 32-year-old Cory Iverson, who had been with Cal Fire for eight years. Iverson’s wife, Ashley, is pregnant, and they have a 2-year-old daughter, according to the governor’s office.

Scott McLean, a spokesman for Cal Fire, said Iverson was an engineer with Cal Fire’s San Diego unit and would have been in charge of the fire engine and the engine crew. Iverson died Thursday, McLean said, though further details were not immediately available.

“His bravery and years of committed service to the people of California will never be forgotten,” Gov. Jerry Brown (D) said in a statement.

Iverson’s death came as the Thomas Fire burned northwest of Los Angeles for an 11th day. The fire in Ventura and Santa Barbara counties had burned across nearly 380 square miles by Thursday. Officials said it was 35 percent contained Friday.

Dangerous air quality in the region persisted, forcing some from their homes and others to stay inside much of the time.

Speaking at the annual American Geophysical Union meeting in New Orleans this week, a group of scientists suggested wildfires might be responsible for thousands of deaths in the United States each year due to the tiny particles they put into the atmosphere.

Wildfires fill the air with the byproducts of combustion, including dangerous small particles called PM2.5, which can get into the lungs and bloodstream. A growing body of research has demonstrated that these particles degrade health and can become fatal by causing respiratory, cardiovascular and other health problems.

“If this is the new norm for California . . . and people in California are being exposed to these smoke events regularly, then we would expect this to have an impact on the average lifetime of people in California,” said Jeffrey Pierce, a professor of atmospheric science at Colorado State University who presented his preliminary results at the meeting.

Smoke from the Thomas Fire shrouds the sun and sky over the Pacific Ocean on Dec. 7. (Stuart Palley/For The Washington Post)

Casa Dorinda in Montecito has been in voluntary evacuation for about a week. According to Chief Executive Brian McCague, about 150 of the 225 independent-living residents have left the premises, compared with just a few of the assisted-living or skilled-nursing residents. Given the heavy smoke, those with serious respiratory issues have been moved to the medical center, where they can be more closely monitored, McCague said. In addition to safety, he has made sure to keep residents informed — and entertained.

“Every other day we’ve been holding town hall meetings with our residents to keep them apprised,” McCague said. “We’re suggesting it’s best just to stay in. We bring movies, games into the building. We do our best to keep them busy.”

Fordyce, the Casa Dorinda resident, said he has been occupying his time in the exercise room.

“Usually I play tennis, but I haven’t been playing in this bad weather,” Fordyce said. “And I gamble on the stock market.”

Life elsewhere in Montecito was beginning to get back to normal, with many local businesses opening up shop on Friday for the first time since the fire hit.

“Some people are just carrying on,” said Vivien Alexander, 50.

Alexander originally headed north to escape the smoke — to Pismo Beach — with her husband and two sons. But the smoke eventually made its way up to them. So they put their children on a flight to see family in South Africa and she and her husband returned home.

While the blaze is being steadily contained, the air quality in the region is still rated by AirNow as “unhealthy for sensitive groups,” meaning elderly people, children, and anyone suffering from heart or lung disease. It’s a feeling to which Alexander can relate.

“You can just feel it burning in your chest,” she said. “The air quality is so bad, it’s like being in a war zone. The people walking around with masks, the firetrucks marching down the streets, ash falling from the sky. It’s so surreal.”

Mooney reported from New Orleans and Berman reported from Washington.