San Joaquin County is among the first in the state to participate in a nationwide emergency alert system.
The San Joaquin County Office of Emergency Services has put into place a wireless emergency alert system.
Emergency Services Director Mike Cockrell says a text alert will go out to mobile phones in an area where a disaster or public danger has occurred.
COCKRELL: "Any cell tower, if you are in that affected area, will send out that notification to your phone, you will know what's happening right where you are at.
Cockrell says it's not necessary to sign up for this, and most mobile phones will pick up the alert.
COCKRELL: "Your cell phone will have its own particular sound when that emergency comes over and it forces a vibration onto your cell phone so you don't have to do anything about it, it's automatically done for you."
In coming weeks, the emergency system will also be able to send alerts to home computers, highway bulletin boards, and even public address speakers in shopping malls.