The blaze, dubbed the Silverado Fire, scorched 7,200 acres with 0% containment as of Tuesday morning, according to the Orange County Fire Authority. Approximately 70,000 homes were under an evacuation order in Irvine and another 6,000 homes in Lake Forest were also under an evacuation order. No structures were confirmed lost, according to officials.
The fire was reported just after 6:45 a.m. Monday at 10 acres in size in the area of Santiago Canyon and Silverado Canyon roads, according to OCFA.
Southern California Edison indicated its equipment is under investigation as a possible source of the Silverado Fire.
The company submitted paperwork to the California Public Utilities Commission which stated:
"Summary: SCE submits this report as it may involve an event that meets the subject of significant public attention or media coverage reporting requirement. Preliminary information reflects SCE overhead electrical facilities are located in the origin area of the Silverado Fire. We have no indication of any circuit activity prior to the report time of the fire, nor downed overhead primary conductors in the origin area. However, it appears that a lashing wire that was attached to an underbuilt telecommunication line may have contact SCE's overhead primary conductor which may have resulted in the ignition of the fire. The investigation is ongoing."
At least 500 fire personnel rapidly launched an aggressive fight against the flames as winds caused the blaze to move with a "moderate rate of spread," eventually jumping the 241 toll road and forcing people from their homes, officials said.
Two hand crew firefighters, ages 26 and 31, both suffered serious burns, OCFA Chief Brian Fennessy announced during a press conference Monday afternoon.
WATCH: Silverado Fire near Irvine rages out of control
The firefighters have 65% and 50% burns on their bodies, respectively, both second- and third-degree burns. Both are being treated at the Orange County Global Medical Center and are intubated in the ICU.
"This is a tough fire, we're experiencing winds, very high winds, very low humidity. Our firefighters are some of the bravest, if not the bravest in the world- this is a very hazardous job," Chief Fennessy added.
Mandatory evacuations were ordered for thousands of residents.
"This fire is going to continue to cross and encroach upon the homes in multiple areas. So, our priority right now is getting people evacuated and out of the path of the fire," said Fennessy, who stressed that residents should immediately heed evacuation orders without delay.
Irvine-area schools closed on Monday and Tuesday, including UC Irvine.
There was no immediate word on the cause of the fire.