AT&T said Thursday its wireless network was back after an outage knocked out cellphone service for its users across the U.S. for hours.
“We have restored wireless service to all our affected customers,” the Dallas-based company said in a statement posted on its website Thursday afternoon. “We sincerely apologize to them.”
Outage tracker Downdetector noted that outages, which began at about 3:30 a.m. ET, peaked at around 73,000 reported incidents. AT&T had more than 58,000 outages around noon ET, in locations including Houston, Atlanta and Chicago. The carrier is the country’s largest, with more than 240 million subscribers.
By 5 p.m. ET, the reports were down to about 1,200.
Cricket Wireless, which is owned by AT&T, had more than 9,000 outages at one point but the reports had also tailed off later in the afternoon. Users of other carriers, including Verizon and T-Mobile, also reported issues but those companies said their networks were operating normally and the problems were likely stemming from customers trying to connect to AT&T users.
Some iPhone users saw SOS messages displayed in the status bar on their cellphones. The message indicates that the device is having trouble connecting to their cellular provider’s network, but it can make emergency calls through other carrier networks, according to Apple Support.
So far, no reason has been given for the outages. But Lee McKnight, an associate professor in the iSchool at Syracuse University, cited the most likely cause of the outage as a cloud misconfiguration, or human error.
“A possible but far less likely outcome is an intentional malicious hack of ATT’s network, but the diffuse pattern of outages across the country suggests something more fundamental,” McKnight said in an emailed statement.
The Federal Communications Commission contacted AT&T about the outage and the Department of Homeland Security and FBI were also looking into it, National Security Council spokesman John Kirby said.
The FBI acknowledged it had been in touch with AT&T. “Should we learn of any malicious activity we will respond accordingly,” the agency said.
The outage also raised concerns on Capitol Hill.
“We are working to assess today’s disruption in order to gain a complete understanding of what went wrong and what can be done to prevent future incidents like this from occurring,” said a statement issued by Cathy McMorris Rodgers, a Washington Republican who chairs the House Energy and Commerce Committee, and Ohio Republican Bob Latta, chair of the Communications and Technology Subcommittee.
When did the outage start?
AT&T had more than 58,000 outages around noon ET, in locations including Houston, Atlanta and Chicago. The outages, which began at approximately 3:30 a.m. ET, peaked at around 73,000 reported incidents. The carrier has more than 240 million subscribers, the country’s largest.
What is the SOS mode?
Some AT&T iPhone customers saw SOS messages displayed in the status bar on their cellphones. The message indicates that the device is having trouble connecting to their cellular provider’s network, but it can make emergency calls through other carrier networks, according to Apple Support.
What is Wi-Fi calling?
AT&T urged customers to connect to Wi-Fi to use their phones. Wi-Fi calling is a built-in feature on most Android devices and iPhones and can be turned on under the phone’s settings.
“Some of our customers are experiencing wireless service interruptions this morning. We are working urgently to restore service to them. We encourage the use of Wi-Fi calling until service is restored,” AT&T said in a statement.
If Wi-Fi isn’t available, there are few options for cell phone users. It’s possible to switch services if a phone is unlocked, but that requires signing up online and porting your phone number.
Some apps, including Google Maps, have limited service offline. Payment apps also do not use a phone’s cell service to work and should also be useable.
What caused the outage?
AT&T has stayed mum so far on what caused the outage.
