Why does my phone say SOS? What you should know about cell phone failures

According to Downdetector.com, a website that monitors outages in real time, Verizon users were the most affected, followed by users of AT&T, T-Mobile and US Cellular.

With more than 2,000 Verizon outages, Phoenix was one of the hardest-hit cities. The increase in outage reports began around 6:30 a.m. and continued to increase beginning at 8:00 a.m. Arizona time. Downdetector estimates that more than 37,000 Verizon customers and hundreds of other providers were affected.

The service outage also caused some to see an SOS icon where cell service would normally appear on the screen. Here’s what it means and how to fix it.