Is Verizon down? Users report widespread network outages in multiple US cities—What does SOS mean on your phone?

Telecom operator Verizon Communications' network was down for tens of thousands of users across US on Wednesday, according to outage-tracking site Downdetector.com.

The telecom operator said it was aware of the problem and that engineers were working to determine the cause and fix it.

“We understand how important reliable connectivity is and apologize for the inconvenience.”

(This is a developing story. More to come)