More evacuations are underway in Southern California, as officials fear that the seemingly unstoppable wildfires could consume even more homes. More than 1,200 houses have already been destroyed in San Diego County, according to its director of emergency services. A big part of the areas evacuation plan incorporates the use of Reverse 911, a modern-day phone tree where residents get a call when there’s a disaster or emergency.

This morning, fresh rounds of Reverse 911 evacuation calls are being placed to more than 400 residents in Valley Center, California, just east of Carlsbad. The town is being threatened by the 20,000-acre Poomacha fire, which started overnight on the La Jolla Indian Reservation.

The fires in Southern California are testing the relatively new phone-alert system that was put in place in the San Diego area just two years ago following a 2003 wildfire, which claimed 15 lives and destroyed nearly 5,000 homes. The county spent several hundred thousand dollars on the program and not long after, residents began signing up.

More than half a million people in the San Diego area received emergency phone calls once the fires started consuming neighborhoods. The system calls both listed and unlisted home telephones and delivers a pre-recorded 30-second message. It is credited with making up to 400,000 calls an hour.

The system is in place in other communities — large (Philadelphia and Providence, Rhode Island) and small (West Point, Georgia) — and alerts residents to a range of emergencies, from natural disasters to rabid animals.

Click here for more information on San Diego's Reverse 911 system.

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Heather Nauert currently serves as a news anchor for FOX News Channel (FNC) and also provides viewers with the top headlines of the day during FOX & Friends (weekdays 6-9AM/ET). Nauert originally joined FNC in 1998 and rejoined as an anchor in 2007.