ORLANDO, Fla. – A massive cellphone outage reported in the U.S. by AT&T customers is now over.
Starting early Thursday, AT&T customers started seeing the service on their phones switch to SOS mode, which means only emergency calls can be made.
“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 has more than 240 million subscribers, the country’s largest.
“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.
Customers of other carriers may have been affected by the AT&T outage.
“Verizon’s network is operating normally. Some customers experienced issues this morning when calling or texting with customers served by another carrier. We are continuing to monitor the situation,” Verizon said.
T-Mobile said that it did not experience an outage.
“Our network is operating normally. Down Detector is likely reflecting challenges our customers were having attempting to connect to users on other networks,” T-Mobile said.
So far, no reason has been given for the outages, but Lee McKnight, associate professor in the iSchool at Syracuse University, believes the most likely cause is 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.