Emergency broadcast messages
When you set up the emergency broadcast messages feature, public warning messages (SMS or MMS) are sent to your device to warn you of possible threats to safety in your area. Examples of emergency broadcast messages include severe weather warnings, missing child alerts, and national emergencies.
Depending on your service provider, emergency broadcast messages don't contribute to data usage in your wireless service plan.
You can view emergency broadcast messages that you receive from the Advanced settings screen in the Messenger app.
This feature might not be supported, depending on your region, service provider, or wireless network. For more information, contact your service provider or administrator.