SAN MARCOS, Calif. - Fire crews were making good progress against a brush fire in San Marcos that threatened two homes for a short time Tuesday afternoon, a San Marcos fire official said.

The fire burned about 10 acres west of North Twin Oaks Valley Road between Cassou Road and West La Cienega Road, according Battalion Chief Rick Vogt. A total of 78 firefighters from Cal Fire and San Marcos and Escondido fire departments were battling the blaze, Vogt said.

Live Sky Fox helicopter video showed two water-dropping helicopters and two air tankers working to control the blaze. Ground crews spread across the burning hillside in an effort create a containment line and spray down hot spots.

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As of 4:20 p.m., crews had a containment line around 30 percent of the fire and structures were no longer in immediate danger, Vogt said. The fire's advance had slowed and crews had released both air tankers. The helicopters were continuing water drops, he said.

Vogt estimated that it would be several more hours before crews had the fire fully contained, but firefighters would remain at the scene until the fire was completely controlled.