One of six major wildfires burning in the region, the Thomas Fire is already the fourth largest in California history, Cal Fire said.
Authorities said it had scorched more than 394 square miles by early Friday.
Cory Iverson, 32, had been with Cal Fire for eight years, according to officials.
A spokesman for Cal Fire said Iverson was an engineer with the San Diego unit. He is survived by his pregnant wife and a 2-year-old daughter.
Ventura County Sheriff Geoff Dean called for a moment of silence during a meeting for Fillmore residents Thursday night.
Iverson was with a strike team of two or three other crew members when he was killed, she said.
"This incident has shaken our organization to the core", Meacham said.
One other death has been connected to the Thomas Fire: a woman who was killed in a vehicle crash while evacuating last week.
Some evacuations were lifted and the risk to the agricultural city of Fillmore was diminishing.More news: Sonia retiring only as President, not from politics : Congress
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Dozens of firetrucks and firefighters were on the property ready to go to work if the wind pushes flames toward the historic property.
The National Weather Service predicted an overnight Sundowner, the local name for a northerly wind that sweeps down the face of the Santa Ynez Mountains toward Santa Barbara and out to sea.
That fire burned down 157 structures, most in its destructive first hours.
Santa Barbara has had only a tiny amount of rain since October 1, the start of the new water year, and is more than 3 inches (7.6 centimeters) below normal to date.
Since the blaze broke out on December 4, it has burned destroyed 970 buildings - including at least 700 homes.
Pimlott said he was "deeply saddened" by Iverson's death but added that fire crews were continuing to focus on their mission.
On Wednesday, Cal Fire tweeted that more than 8,000 firefighters and almost 1,000 engines were battling the blaze, which was then at 238,500 acres, but was 30 percent contained.
High winds and dry conditions continue to hamper efforts to contain the Thomas Fire, with few signs of improvement heading into the weekend, according to CNN meteorologists.