If you see SOS mode on your phone today, you are not alone. Verizon, the largest wireless carrier in America, is experiencing a massive outage affecting users across the US.

Around 10 a.m. ET, users reported being unable to make calls, send texts, or use mobile data. Many added that their phones were on SOS mode.

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Phones enter SOS mode when they are not connected to their carrier’s network, because they are in an area with poor coverage or due to a technical problem. Considering that most of today’s reports come from major cities, the latter problem appears to be the case.

Fortunately, a phone in SOS mode can still make emergency calls, and you may also be able to make calls and send text messages if you have a Wi-Fi connection.

Shortly before noon, Verizon said in a message on The Verizon Support

A map on DownDetector.com (owned by Ziff Davis, ZDNET’s parent company) shows heavy outages in East Coast cities like Atlanta, Charlotte, NC and New York, but also, to a lesser extent, in Chicago, Detroit, Los Angeles. Angeles, San Francisco and Phoenix. More than 100,000 users have reported an outage. Disruptions were still being reported at 2 p.m.

When I used Verizon’s “Check Network Status” tool, everything seemed to function normally. My first thought was that this might be related to the damage caused by Hurricane Helen, which devastated parts of Florida, Georgia, Tennessee and North Carolina. However, many people affected by the Verizon problem today are not in the path of the storm.

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What can you do if your phone is stuck in SOS mode? In other cases, restarting the device or toggling airplane mode on and off helps. In the current case, users are reporting that this doesn’t work, so there doesn’t seem to be a solution at the moment. If you need any kind of connectivity beyond an emergency call, you’ll need to find Wi-Fi.

As soon as we get more information about the cause of the problem, we will post an update here.