California authorities late Monday said a firefighter died battling the massive Mendocino Complex fires that have burned 336,399 acres in the state and forced mandatory evacuations.
The firefighter was not immediately identified, and the next-of-kin was being notified.
Commanders from CAL FIRE and the U.S. Forest Service confirmed the death. The firefighter is the sixth fatality in a matter of weeks.
About 3,900 firefighters, including a crew of 40 volunteers from New Zealand, had been battling the fire, contending with temperatures in the high 90s and winds gusting to 25 mph.
The wildfire is the biggest recorded in California and is located about 100 miles north of San Francisco. The fire spread quickly due to what officials said was a perfect combination of weather, topography and abundant vegetation turned into highly flammable fuel by years of drought.
The Mendocino Complex is actually two blazes burning so close together that authorities are attacking them as one, a common practice at Cal Fire. The fires started within an hour of each other about 15 miles apart. Officials have not determined the cause of either one.
When the fire started July 27, thousands of firefighters were hundreds of miles north battling a massive blaze that spread into the city of Redding, destroying more than 1,000 homes, in addition to a dozen other major blazes.
Full containment is not expected on the until Sept. 1, fire officials said.
The Associated Press contributed to this report