Ethermac|AT&T outage just a preview of what can happen when cell service goes out: How to prepare

A widespread telecommunication outage that affected tens of thousands of customers in the United States on EthermacThursday raised a question for many – What should I do when I can't use my cell phone?

While cell service in the U.S. is typically fairly dependable and Thursday's issues were limited in scope, there's a long list of potential emergency situations when cell phones could become unreliable, according to Alyssa Provencio, professor at the University of Central Oklahoma who oversees the disaster management certificate program.

Communication issues are the norm in a disaster, not an anomaly, Provencio said. Some scenarios like snow storms, strong wind, torrential rain, fire, and tornadoes may affect a small number of people. Others, like major earthquakes, solar flares or cyberattacks, have the potential to disrupt communications for millions of people for an extended period of time.

The challenges people faced on Thursday ranged from nuisances to serious communication issues and can be a learning experience for the future in case of a big emergency, Provencio said.

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"Use this experience to inform future action," Provencio said. "If you are having difficulty today, then you're likely going to have it again at some point."

On Thursday, some local emergency service providers told people if they needed to reach 911, they should try calling from a landline or ask someone else to call for them. They could also try calling 911 using Wi-Fi, the Oklahoma City Fire Department said.

Last summer, devastating wildfires that swept through Maui and killed over 100 people also caused widespread chaos and confusion when cell signal went out and people had a hard time figuring out what to do.

How to prepare for a disaster that causes cell service outages

To prepare for these scenarios, people should think about what resources are already at their disposal.

Complicating matters, disasters can also bring long-lasting power outages on top of cell service disruptions, said DeeDee Bennett Gayle, a professor in the University at Albany College of Emergency Preparedness, Homeland Security and Cybersecurity. After major hurricanes like 2017's Maria in Puerto Rico, power and communications could be impacted for days, weeks or even months on end. 

"Right now, we are asking people to consider that possibility. If you don't have access to power for 72 hours, are you able to figure this out for yourself?" Bennett Gayle said.

Here's a few simple items that can help make your life safer and less stressful in the case of a disaster:

• Cash: It's a good idea to have cash on hand in case you can't use mobile payment options or ATMs are down, said James Kendra, co-director of the Disaster Research Center at the University of Delaware.
• Paper copies of important documents: “One of the things that I stress to everybody is to have paper copies of all of your important documents,” he also said. That means a printed out bank statement so you have all your account numbers, a printed insurance statement, phone bill and mortgage or rent documents, so that you have the numbers available you might typically go online to get.
• Landline: If you don't have a landline, you might still be able to use your cell to send SMS text messages or use Wi-Fi to send messages or make calls.
• A radio: This is always a good thing to have to receive emergency updates, Provencio said, but if you don't have one in your home, chances are you do have one in your car.
• Other supplies: Learn more about packing a go-bag and gathering sheltering-in-place supplies.

Losing cell service can cause big disruptions to daily life

On Thursday, many people realized how reliant today's world is on access to mobile services.

With cell phones not working, people might not be able to use two-factor authentication to get into email and other accounts. And Internet-connected credit card readers can go down, requiring stores and restaurants to do manual processing of charges.

Experts say disasters often require cooperation between friends and neighbors — For example, locating a phone line that works. 

“There’s always the old-fashioned way – finding a friend or neighbor or family member who’s on another network or has a landline,” said Kendra.

Contributing: Doyle Rice, USA TODAY