READING, Pa. – If your phone suddenly showed “SOS,” no bars, or just stopped working Wednesday afternoon, you weren’t alone.

Thousands of Verizon customers across the country reported losing wireless voice and data service as a nationwide outage hit around midday.

Verizon acknowledged the issue in a statement posted on social media:

“We are aware of an issue impacting wireless voice and data services for some customers. Our engineers are engaged and are working to identify and solve the issue quickly. We understand how important reliable connectivity is and apologize for the inconvenience.”

So far, Verizon has not said what caused the outage or when service will be fully restored.

Cybersecurity experts say there are several possible explanations, but no confirmed cause yet.

“It could be anything from hardware problems to software problems… or even a cybersecurity event,” said Eric Robuck, a cybersecurity professor at Alvernia University.

Here in Berks County, emergency officials are urging residents not to panic.

In a statement, Brian Gottschall, Director of the Berks County Department of Emergency Services, said:

“Customers needing to reach 9-1-1, and who are unable to get through because of the outage, should use whatever means they would use to summon help if their cell phone was dead.”

Robuck says the best protection against outages is having backup options but that’s not realistic for most people.

“Redundancy is a very good thing to do in your life, but having two cell phones from two different carriers can be quite expensive,” he said.

Other major wireless carriers, including AT&T and T-Mobile, say their networks are operating normally.