AT&T reveals the reason for its massive outage – and it wasn’t a cyberattack

AT&T is still assessing the impact of yesterday's drama (Image credit: Shutterstock / Jonathan Weiss)

We're still reeling from the scale and widespread impact of yesterday's huge AT&T outage, and information about what caused the breakdown in cell coverage is now coming to light. And it seems as though a good old-fashioned technical error was to blame.

"Based on our initial review, we believe that today's outage was caused by the application and execution of an incorrect process used as we were expanding our network, not a cyberattack," said AT&T in an update posted on its website.

"We are continuing our assessment of today's outage to ensure we keep delivering the service that our customers deserve," the statement continued. Somewhere in the region of 2 million reports were filed on Downdetector yesterday, as the incident progressed.

Spokesperson Jim Greer told the Washington Post that AT&T would continue to monitor the situation. The Post is also reporting that the FBI, the Department of Homeland Security, and the Federal Communications Commission are also investigating.

More to come

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Yesterday's cell network outage was the biggest in recent memory, with problems apparently starting around 3.30am Eastern Time as the US was waking up. We saw reports of issues across multiple states, and 911 calls were also impacted.

While there were also reports of connection mishaps from Verizon and T-Mobile customers, it seems as though they were mostly related to getting through to people on AT&T – so the main outage seems to have only affected one carrier.

Of course this was a massive inconvenience for AT&T customers, who were unable to make personal or work calls while the incident was happening. AT&T has hinted that some compensation will be offered, but as yet we don't have any details on that.

No doubt there's lots more to come on this as AT&T weighs up what went wrong and how it can stop it from happening again. In the meantime, you might want to make sure you know how to set up Wi-Fi calling on your smartphone.

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David Nield
Freelance Contributor

Dave is a freelance tech journalist who has been writing about gadgets, apps and the web for more than two decades. Based out of Stockport, England, on TechRadar you'll find him covering news, features and reviews, particularly for phones, tablets and wearables. Working to ensure our breaking news coverage is the best in the business over weekends, David also has bylines at Gizmodo, T3, PopSci and a few other places besides, as well as being many years editing the likes of PC Explorer and The Hardware Handbook.