AT&T was down nationwide and the outage affected calls to 911 as well. The outage was confirmed by the company at 9:49 p.m. EST and at 10: 30 p.m. EST, the company said in a Twitter post that the issue had been resolved.

"We are aware of a service issue affecting some calls to 911 for wireless customers and we’re working to resolve it as quickly as possible. We apologize for this inconvenience,” an AT&T spokesman told WFAA ABC earlier.

The company's acknowledgement came after law enforcement agencies in Florida, Maryland, Texas, Tennessee, Alabama, Ohio, Colorado, Virginia, Illinois, and the District of Columbia told residents about the outage. They also suggested other ways to get in touch with emergency services.

Many counties provided backup numbers, which customers could call if they weren’t able to reach 911. For Example, the Apopka Police Department addressed the outage at 10:20 p.m. and released a statement to Florida Today saying,” The Apopka Police Department released a statement saying, "A reported issue with AT&T cellular service Wednesday evening is preventing customers from calling 911 for emergency assistance in parts of the southeastern United States, including Orange County and Apopka, Maitland and Eatonville.

"In cases of actual emergencies tonight, AT&T cellular phone customers who cannot reach 911 in Apopka, Maitland and Eatonville should call the city's emergency dispatch center at 407-703-1757. This is only for AT&T customers -- others should call 911."

At around 10:35 p.m., reports started emerging from different states and counties that the problem with AT&T’s network had been resolved. Florida Today reported at 10:44 p.m. that the outage in Florida had been resolved.

The company hasn’t yet provided any details on why the outage happened or how it was resolved.

The chairman of Federal Communications Commission also announced the agency was investigating the service disruption.

According to Fortune, AT&T had 135 million wireless subscribers in the U.S., as of Dec. 31.