Crews contain grass fire on San Bruno Mountain in Brisbane

BRISBANE, Calif. - Firefighters are at the scene of a three-alarm grass fire burning on San Bruno Mountain off of Guadalupe Canyon Parkway in Brisbane. As of 2:00 p.m., the fire is 5-acres and 100 percent contained.

The fire was first reported at 10:55 a.m. Thursday, according to reports. There's no word on what caused the fire.

The City of Brisbane has issued a voluntary evacuation order for Humboldt, Kings, Margaret, Paul and San Mateo.

KTVU has reached out to North County Fire and San Mateo County Fire and is waiting to hear back.

The fire is burning directly under PG&E transmission lines. We've reached out to PG&E, who confirms they're aware of the fire, but offered no further information.

Meteorologist Mark Tamayo reports the area is currently experiencing warm, gusty winds and that conditions are dry.

Within the first hour, we've seen multiple firefighting aircraft assisting crews on the ground. These include fire-retardant carrying airplanes, as well as helicopters equipped with water buckets.