The wireless carrier said a weather-related power failure in Bloomfield, Mich., was the cause of the problem. The disruptions varied for subscribers, as some experienced dropped calls, while other had no access to voice or data services. Other users experienced slower mobile data service, or no access to AT&T's 3G data network.
"The situation resulted in intermittent disruption of mobile services for customers in some Midwest states," an AT&T representative said in a statement. "Backup power was restored later Sunday morning, and impacted equipment was restored to service Sunday afternoon."
Subscribers flooded gadget and technology Web sites to chime in on the outages, and to voice their displeasure.
"I'm in the west suburbs of Chicago, and I've had no service for the past 4 hours at least," wrote a commenter on Engadget Sunday. "I called AT&T to see what was going on, and one of their customer service doofuses told me there 'might' be an outage affecting my area. Gee, ya think?"
AT&T said virtually all service traffic is running normally now, and it's working to restore the few remained cell sites that were still down. The voice and data failures came at a particularly bad time, as Sunday was the day that Wal-Mart began selling the iPhone 3G.
The retail giant began selling the 8- and 16GB models for a slightly discounted price in thousands of stores Sunday, including many in the affected regions. This could potentially give new users a bad first impression of the touch-screen smartphone, which is already facing a few lawsuits for connectivity and reception issues.