A small brush fire was sparked Tuesday morning near the connector of Interstate 805 and state Route 54.
Estimates put the size of the fire at just over an acre., officials said, when the forward spread of the fire was checked.
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By 11:30 a.m., CalTrans tweeted out that all northbound lanes of the I-805 ramp to SR-54 had been shut down due to the fire.
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A fire captain at the scene told NBC 7 that the fire was believed to have started in an area by the freeway known for homeless encampments.
The spread of the fire was initially fairly rapid, officials said, prompting a request for a firefighting aircraft, which made two drops to aid crews on the ground.
Nobody was injured in the fire, which was fought by firefighters from National City, San Diego, Chula Vista, Bonita and Coronado.
By noon, the flames had largely been extinguished and fire crews were mopping up hot spots.