© Mike Blake / ReutersAT&T
Some Verizon and T-Mobile customers also reported outages, though both companies said those affected had been trying to contact AT&T users.
Over 32,000 AT&T outages were reported by customers at about 4 a.m. ET on 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, according to the site.
That number surged to more than 71,000 just before 8 a.m. ET.
A little over 1,100 T-Mobile outages and about 3,000 Verizon outages were reported as of 7 a.m. Thursday.
It's not clear what triggered the service disruption.
AT&T acknowledged the issue Thursday morning, saying: "Some of our customers are experiencing wireless service interruptions this morning."
The company has since made progress in restoring service.
"Our network teams took immediate action and so far three-quarters of our network has been restored," AT&T said in a statement. "We are working as quickly as possible to restore service to remaining customers."
Cricket Wireless, which is owned by AT&T and uses its network, is also experiencing cellular problems. More than 13,500 customers reported outages as of 8 a.m. ET on Thursday. The number dipped to around 10,000 by 10 a.m.
"Allow us to explain that there is a nationwide network incident impacting multiple services," the company wrote on X. "It is Cricket's top priority to restore service to full capacity as quickly and safely as possible."
Verizon said Thursday morning that the outages are not affecting its network directly, only customers trying to reach another carrier.
T-Mobile also said early Thursday that the network didn't suffer an outage and is operating normally, and Downdetector numbers likely reflect customers attempting to reach users on other networks.
The outages pose a concern as some people may be unable to call 911 in the case of an emergency.
The San Francisco Fire Department said on X that it was aware of an issue affecting AT&T wireless customers' making and receiving phone calls, including to 911.
"The San Francisco 911 center is still operational," the office said. "If you are an AT&T customer and cannot get through to 911, then please try calling 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."
Similarly, Chicago's Office of Emergency Management and Communications, Virginia's Prince William County Police Department, and North Carolina's Charlotte-Mecklenburg Police Department have issued warnings on X alerting the public about the outage while acknowledging some customers were briefly unable to contact 911.
Atlanta Mayor Andre Dickens said in a statement that the city is gathering information to assist in resolving the issue.
"Atlanta's e-911 is able to receive inbound and make outbound calls. We have received calls from AT&T customers that their cellular phones are in SOS mode," Dickens said.
Apple Support confirmed that iPhone users seeing SOS displayed in their status bar can still make emergency calls through other networks.
Agencies across the country are urging people to refrain from calling 911 to test their service. The line is for real emergencies only.
Comment: It may be a sign of America's increasingly deteriorating infrastructure, and/or it may be notable in light of the following: