FCC says it will investigate AT&T wireless 911 outage

— -- The Federal Communications Commission said Wednesday night it will investigate "the root cause" of an outage that prevented AT&T wireless customers in several states from connecting to 911.

FCC chairman Ajit Pai tweeted, ".@FCC AT&T has reported to me that 911 service is now restored. The @FCC will investigate the root cause of the outage and its impact."

At 10:30 p.m. ET, Dallas-based AT&T tweeted, "Issue has been resolved that affected some calls to 911 from wireless customers. We apologize to those who were affected."

AT&T confirmed the outage about 40 minutes earlier, at 9:49 p.m. ET, tweeting, "Aware of issue affecting some calls to 911 for wireless customers. Working to resolve ASAP. We apologize to those affected."

AT&T's tweet came after law enforcement agencies in several states, including Florida, Maryland, Texas, Tennessee, Alabama, Ohio, Colorado, Virginia, Illinois, and the District of Columbia informed residents about the outage, and suggested other ways to contact emergency services.