The FCC has launched a federal investigation into telecommunications company CenturyLink after a failure of the company's systems in Louisiana led to 911 outages across the US on Thursday. Customers in several markets were left without Internet, and vital services like 911 were down temporarily, with local police departments urging residents to call their local numbers with emergencies.

FCC Chairman Ajit Pai has ordered the investigation, calling the outage "completely unacceptable, and its breadth and duration are particularly troubling."

The nationwide @CenturyLink service outage and the delay in restoring critical 911 capabilities is unacceptable. I have spoken to CenturyLink to express my concerns and have directed the @FCC’s public safety staff to launch an investigation. My statement below. #publicsafety pic.twitter.com/HgQas1xtyB

— Ajit Pai (@AjitPaiFCC) December 28, 2018

Here's a breakdown of the affected areas and a map of the outages:

>>4502768
>https://t.co/MGhTKFXIVx

States involved in 911 outage.
Washington
Colorado
California
Texas
Arkansas
Louisiana
Indiana
Kentucky
West Virginia
Virginia
Pennsylvania
Florida
Maryland
(Washington D.C.) pic.twitter.com/wjBZ1nkehM

— Psalm2:1 ⭐⭐⭐ (@graceandblood) December 28, 2018

Out

CenturyLink tweeted Thursday that its engineers had identified the problem and are working to fix it.

CenturyLink engineers have identified a network element that was impacting customer services and are addressing the issue in order to fully restore services. We estimate services will be fully restored within 4 hours. We apologize for any inconvenience this caused our customers.

— CenturyLink (@CenturyLink) December 28, 2018

According to the Boston Globe, people calling 911 might hear a busy signal or a recording saying "all circuits are busy." Callers may also get connected to an emergency call center that they weren’t expecting. In addition to 911, Gizmodo reported that phone services at the Department of Correction and the Department of Education in Idaho were offline as well.