AT&T, Cricket Wireless cell service fully restored following hours-long outage

AT&T said the outage on Thursday that left tens of thousands of customers without service for hours was due to "an incorrect process" used as the company was expanding its network, according to its website. 

"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 cyber attack," according to an update from AT&T. 

The company said its assessment of Thursday’s outage is ongoing. 

The major cellular network outage had been resolved by mid-afternoon. Many users reported that their cellphones were stuck on SOS, meaning there was no service, and their devices were in the process of searching for an available cellular network. 

"We have restored wireless service to all our affected customers. We sincerely apologize to them," read a statement from AT&T, received just after 3 p.m. "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."

In addition to AT&T’s incident, other wireless carriers such as Cricket Wireless, T-Mobile, Verizon, and Boost Mobile reported outages. Cricket Wireless had the most reported outages after AT&T, followed by Verizon, T-Mobile, and Boost Mobile. The company said its customers' cell service had been fully restored by 4 p.m. (ET).

"We sincerely apologize to them," the Cricket Wireless statement read. "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."

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Reports of the AT&T outage began coming into Downdetector shortly before 4 a.m. About an hour later, those reports skyrocketed as millions were talking about the issue on Twitter.