Authorities in San Francisco (California) reported that customers of the AT&T telephone company were affected by a failure that left them without service for several hours.

"We are aware of an issue impacting AT&T wireless customers from making and receiving any phone calls (including to 911). We are actively engaged and monitoring this." the city's Fire Department wrote on X.

In that sense, the department explained that the San Francisco 911 center is still operational and that those affected by the failure should try to call from a landline. "If that is not an option then please try to get ahold of a friend or family member who is a customer of a different carrier and ask them to call 911 on your behalf," the department said.

"We are working to restore service"

AT&T acknowledged the failure on its X account and maintained that it is working to restore service.

"We sincerely apologize for the inconvenience that is happening and 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." the company wrote on the social network.

According to reports from users and media outlets - such as NBC - some Verizon and T-Mobile customers also reported outages. However, complaints about failures at these companies were less widespread than those at AT&T.

Meanwhile, NBC detailed that "Over 32,000 AT&T outages were reported by customers at about 4 a.m. ET Thursday. Reports dipped then spiked again to more than 50,000 around 7 a.m., with most issues reported in Houston, Chicago, Dallas, Los Angeles, and Atlanta".