AT&T this week started pushing out a small software update to iPhone 5 and iPhone 4S owners, adding Wireless Emergency Alerts. The carrier rolled out the system about twelve months ago as part of the FCC's CMAS program mandated by law, which provides customers with up to date AMBER alerts, Emergency alerts and Presidential alerts.

All three are on by default in the Notification Center, but two of the three can be turned off: AMBER alerts and Emergency alerts. AT&T said once the update is pushed to your device, a Carrier Settings Update message will appear, prompting you to download the new alerts. The update is only being sent to iPhone 5 and iPhone 4S devices running iOS 6.1 or higher.