Multiple media sources are reporting AT&T downtime on their wireless network. Data and text messages are said to be unaffected. No word yet what the cause of the outage is or the estimated time of repair.
AnnArbor.com, AT&T Wireless problems affecting calls in Ann Arbor.
AT&T community forums: Metro Detroit South East Michigan Outage
Update: 10:29 a.m. Reports from the community forum are that service is coming back.