In short, when you see SOS on your phone, it means you're not connected to a cellular network. "If you see SOS or 'SOS only' in the status bar, your device isn't connected to your cellular network, but you can still make emergency calls through other carrier networks," reads an Apple support page on the feature.

When iPhones aren’t connected to a cellular network, they will typically alert the user by giving an indication in the phone’s status bar. Those notifications usually say “No Service” or “Searching,” but your phone may also say “SOS” or “SOS only.”

Verizon outages today, Wednesday, Jan. 14, hit the U.S. with customers reporting "SOS" mode on their phones, Fios outages, home internet and Wi-Fi outages and other Verizon service issues. In an update on X today, Verizon said it is "working on the issue."

Tess Coward, a 27-year-old PR professional based in New York City, woke up feeling under the weather on Wednesday. But without the ability to make phone calls or receive text messages, she couldn’t get in touch with her doctor or log into the provider’s patient portal.

Verizon, the country's largest cellphone provider, apologized Wednesday night after issues lasting much of the day left subscribers suddenly left without service and stuck in "SOS" mode.

During the Verizon outage, police warned that contacting 911 could be tricky. Big disruptions can have cascading effects on everyday life.