When a potential emergency happens, it's critical to get information as quickly as possible. Here are some alerts to look out for or opt into:
Wireless Emergency Alerts (WEAs) are used to send SMS messages to WEA-capable mobile devices during emergencies. WEAs are sent by your state and local public safety officials, the National Weather Service, the National Center for Missing and Exploited Children, and the office of the President of the United States.
Many municipalities have their own text and email-based alert systems that are very worth signing up for. San Francisco has Alert SF. To sign up, text your zip code to 888-777 or visit: www.alertsf.org.
Outdoor public warning systems are local sirens and messages broadcast from dozens of points around a city. Check your community's fire or emergency services page to learn more about what systems are in place and when they activate.
Twitter and NextDoor can be great ways to learn about what's happening near you in real time.
Most phones come equipped with emergency notifications, as well as a way to send an SOS call to 911 and your emergency contacts. Access the notifications on an iPhone by scrolling to the bottom of your Notifications, and ensuring Government Alerts are turned on.