AT&T was experiencing some issues Tuesday night that left customers seeing “SOS” instead of their usual bars of service.

“We’ve resolved a software issue that disrupted the ability of a limited number of our customers to connect to our wireless network. We apologize for the inconvenience and we appreciate our customers’ patience as we worked to resolve this issue,” said AT&T spokesperson Jim Kimberly in a statement sent to The Verge.

The number of problem reports tracked by Downdetector started rising after 4PM ET before finally fading out closer to midnight on the East Coast.

Kimberly also said that an explanation posted by The Mobile Report was inaccurate. That outlet said AT&T found internally that a failure at a switching center “has resulted in a cascade of problems, including service delays, the inability to provision new SIM cards, and, for many, a complete loss of network connectivity” that may primarily affect iPhones and other Apple devices.

Update, August 28th: Added statement from AT&T spokesperson noting the issue appears to be resolved.