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- Photos: Blaze erupts in Ventura County
- Link: CAL FIRE Guiberson Fire updates
Firefighters said they will be focusing on the western flank of the fire Thursday.
"Today is our turning point," said Mike Mohler from Cal Fire. "We have the red flag warning, but we don't have the winds."
Mohler said officials hope to have 50 percent containment by the end of Thursday night.
Flames burned near Fillmore overnight. The fire is moving east toward Piru, a rural area, but to the west, the Guiberson Fire is still a threat to ranches, oil production fields and agriculture.
Officials said they are not aware of any major damage to orchards, but expect some trees on the outskirts to be damaged.
The Guiberson Fire began late Tuesday morning, but authorities said a quick response in the air and on the ground helped them achieve 40 percent containment in less than 48 hours.
"That initial assessment, realizing that this thing had potential, getting help to come from all over California and getting it to come quickly, because it's easy to call for 1,000 fire engines, but now to mobilize them and get them here takes time," said Ventura County Fire Capt. Ron Oatman.
The cause of the fire remains under investigation, but authorities said it started near a mulch pile on a ranch. The Sheriff's Department had earlier said that manure may be to blame because when it breaks down it can explode and catch fire.
There are about 1,800 firefighters assigned to the wildfire, and they expect to make significant gains in the coming days.
Fire officials said they hope to have full containment by Saturday.