2024-02-23 07:49:19 ET
Feb. 23 (UPI) -- AT&T said an internal issue and not a cyberattack was to blame for a mass service outage on Thursday.
After announcing that service had been restored to all of its customers as of 1:10 p.m. EST Thursday, the wireless provider said it was still assessing the outage and taking steps to prevent future outages.
"Based on our initial review, we believe that [Thursday's] outage was caused by the application and execution of an incorrect process used as we were expanding our network, not a cyberattack," the AT&T said.
The cellular phone outage started before dawn on Thursday and throughout most of the day, AT&T customers could not get a signal, affecting emergency outlets, municipalities and customers of other cellular companies who were trying to reach services and loved ones who use AT&T.
The website Down Detector said at one point Thursday that more than 71,000 customers reported cellphone issues. Cricket Wireless, which is owned by AT&T and uses its network, has more than 13,000 customers affected.
Verizon said it received 4,300 outage reports but said it was not affected directly by AT&T. Other systems said their problems occurred when their customers tried to reach out to those using AT&T during the outage.
The Federal Communications Commission said its Public Safety and Homeland Security Bureau has opened an investigation into the outage.
"We are in touch with AT&T and public safety authorities, including FirstNet, as well as other providers," the .
White House National Security Adviser communications adviser John Kirby said Homeland Security and the FBI have also been in touch with AT&T.
"We're working very hard to get restoration of services to those that are still without those services," Kirby said Thursday.