Many Verizon customers can’t hear you now. There appears to be a widespread outage of Verizon cell phone service, according to DownDetector, an online site that monitors websites and services.

Verizon users were experiencing an outage on Monday morning, causing many to see the SOS icon. Here's what it means.

An SOS symbol appeared on the screens of iPhone users who use Verizon, where cell service bars are normally shown. According to Apple support, if you're having trouble with phone service and see SOS or "SOS only" in the status bar, your device can still make emergency calls despite not being connected to a phone network.