AT&T's network was hit by a widespread cellular outage Thursday, impacting thousands of wireless customers across the country. Just after 3 p.m. Thursday, the network was fully restored.
"We have restored wireless service to all our affected customers," AT&T said in a statement. "We sincerely apologize to them. Keeping our customers connected remains our top priority, and we are taking steps to ensure our customers do not experience this again in the future."
AT&T did not say what led to the service disruption.
Downdetector, the outage tracking site, began seeing a surge of service problems from AT&T, T-Mobile and Verizon customers starting at around 3 a.m. ET. There also appeared to be network issues for Cricket Wireless, which is owned by AT&T, as well as Consumer Cellular, Boost Mobile and other regional services.
However, a spokesman for Verizon told NBC News that they did not see any issues on their network and believes the problem is with other carriers. Verizon said its customers are only having issues when trying to call a number that is associated with one of the impacted carriers.
T-Mobile also said their networks were operating "normally," and explained the outages reported in Downdetector is likely "reflecting challenges our customers were having attempting to connect to users on other networks."
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The Federal Communications Commission responded to the outage in a Thursday statement.
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"We are aware of the reported wireless outages, and our Public Safety and Homeland Security Bureau is actively investigating," the statement said. "We are in touch with AT&T and public safety authorities, including FirstNet, as well as other providers. "
What does the SOS symbol mean on my iPhone?
Many of the impacted customers with iPhones awoke to an SOS symbol in place of their usual cell signal bars on their phones.
That symbol appears when the device isn't connected to a cellular network. However, according to Apple's support website, iPhones will show "SOS" when there is a nearby network available for "emergency calls."
"When you make a call with SOS, your iPhone automatically calls the local emergency number and shares your location information with emergency services," Apple explains.
If you have designated emergency contacts on your phone, it will send them an automatic text message with your current location after you've made an emergency call. (For information on how to set up emergency contacts, click here).
According to Apple, iPhone models 14 and later can make emergency calls via satellite to contact emergency services when there is no cellular or Wi-Fi coverage available.
Several police departments around the country reported difficulties communicating with city phones. The Charlotte-Mecklenburg Police Department in North Carolina said customers were "briefly unable to contact 911" during the outage.
Many 911centers in several states, including California, Virginia, Massachusetts, Illinois and Texas reported that the outages prevented people from making emergency calls from their cellphones.
The Massachusetts State Police also urged people not to call 911 just to see if the number worked.
