FCC investigating 5-hour AT&T 911 outage

An AT&T logo is seen at a AT&T building in New York City, October 23, 2016. (REUTERS/Stephanie Keith)

The Federal Communication Commission is investigating a widespread AT&T 911 outage that occurred Wednesday evening.

The nearly five-hour outage affected AT&T mobile phone users in at least 14 states and Washington, D.C. from at least 5:49 p.m. until around 10:25 p.m., according to The New York Times.

Law enforcement and emergency response officials in Alabama, Arkansas, California, Colorado, Florida, Indiana, Kentucky, Louisiana, Maryland, Pennsylvania, Tennessee, Texas, Virginia, West Virginia, and Washington posted warnings about the outage on social media, according to the report.

At 10:30 p.m., AT&T said the issue had been fixed. "Issue has been resolved that affected some calls to 911 from wireless customers," the carrier wrote on Twitter. "We apologize to those who were affected."

FCC Chairman Ajit Pai‏ tweeted last night that the agency had received reports about the outage and its public safety staff was looking into the problem. After AT&T restored service, Pai promise that the FCC "will investigate the root cause of the outage and its impact."

AT&T did not say how many people were affected by the problem.

During the outage, the Hendricks County Communications Center in Indiana wrote on Facebook that 911 calls from AT&T customers would not connect. "We have conducted test calls locally and it will just ring," they wrote.

Though there's no word yet as to what caused the outage, if history is any indication, the FCC may slap AT&T with a fine over the incident. The agency in 2015 fined Sprint $1.2 million, T-Mobile $17.5 million, and Verizon 3.4 million over 911 outages.

This article originally appeared on PCMag.com.