Text-based alerts of significant, imminent danger will be able to be sent to most mobile-phone users in a hazardous location in the U.S. beginning Saturday, when the new commercial mobile alert system (CMAS) is scheduled to become operational.

It used to be that messaging, which gained popularity as simple texting or Short Message Service (SMS), was just for teens—a way for them to interact in real-time via their own shorthand tech-speak.