A 32-year-old Cal Fire engineer from northern San Diego County was killed Thursday while fighting the massive Thomas Fire in Ventura County.

Cory Iverson of Escondido died near Fillmore while helping battle the 10-day-old inferno, which has spread over about 242,500 acres and destroyed nearly 1,000 structures.

Iverson, who leaves behind a pregnant wife and toddler daughter, had been with the state agency since 2009, according to Cal Fire Chief Ken Pimlott.

Officials did not immediately disclose how Iverson died.

"More details will be made available as they are confirmed," Pimlott said. "In the meantime, please join me in keeping our fallen firefighter and his loved ones in your prayers (and) all the responders on the front lines in your thoughts as they continue to work under extremely challenging conditions."

Iverson, who was assigned to the Thomas Fire as part of a fire-engine strike team from Cal Fire’s San Diego unit, is survived by his wife, Ashley; 2- year-old daughter, Evie; mother, Denise Butler; stepfather, Scott Butler; and father, Craig Iverson.

"Cory and Ashley are expecting a second daughter this spring," Pimlott said. "Our thoughts and prayers are with Cory’s family and all of his friends and co-workers throughout the department and the fire service."

Cal Fire has assigned an accident-review team to determine the circumstances and cause of the fatality, according to Pimlott, who added that "until this review is complete, there is nothing more I can share."

"What I can say is a heartfelt and deep thank you for the outpouring of support for Cory’s family and the Cal Fire family," the chief said.

Despite the traumatic loss, firefighting personnel "must keep our focus on the fire," Pimlott said. "The firefight in front of us continues to go on," he said.

"The communities we are protecting are depending on us, and we will not fail."

In a prepared statement, Gov. Jerry Brown expressed sorrow over Iverson’s death.

"His bravery and years of committed service to the people of California will never be forgotten," the governor stated.

In Iverson’s honor, Capitol flags will be flown at half-staff. As of late this afternoon, the Thomas Fire, the fourth-largest blaze in California history, was roughly 30 percent contained, according to Cal Fire.

San Diego Firefighter, 32, Killed in Battle Against California’s Fourth-Largest Fire