Toa55/iStockBy JULIA JACOBO, ABC News

(NEW YORK) -- Two Orange County Fire Authority firefighters have been critically injured while battling the Silverado Fire in Southern California.

The fire started Monday morning on vegetation at Santiago Canyon Road and Silverado Canyon Road, according to the City of Lake Forest.

The firefighters were injured near the fire's point of origin around noon, OCFA Captain Jose Gonzalez told reporters during a news conference.

As of Monday afternoon, the blaze had burned 2,000 acres and remained at 0% containment, fire officials said. About 20,000 homes were evacuated, and 500 personnel were fighting the fire.

The injured firefighters are ages 31 and 26 and are both intubated at the hospital, Orange County Fire Authority Chief Brian Fennessy said at a press conference.

One of the firefighters suffered second- and third-degree burns on 65% of his body, while the other sustained second- and third-degree burns on 50% of his body, Fennessy said.

"It's one of the hardest things any fire chief can do, is to report one of the firefighter family members have been injured or worse," Fennessy said. "This is tough for me, tough for all my firefighters."

The fire is continuing to spread due to winds of 20-30 mph, Gonzalez said. The windy conditions were expected to continue into the night.

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