Many CenturyLink customers across the U.S. were without internet Thursday amid a lengthy outage that even affected some Verizon customers.

The outage began early in the day but by late Thursday night, the company tweeted that its engineers had identified a “network element” that was affecting services and expected to fully restore services within hours.

Customers from New York to California reported outages. The outage knocked out 911 emergency call services in parts of western Washington state. Other areas of the country also experiencing 911 outages included parts of Missouri, Idaho and Arizona.

Some ATM machines weren’t working in Idaho and Montana.

Verizon said it had service interruptions in Albuquerque, New Mexico, and parts of Montana as a result of issues with CenturyLink. Verizon said CenturyLink helps handle wireless network data traffic for Verizon and other wireless providers.

Federal Communications Commission Chairman Ajit Pai said that the agency has launched an investigation into the incident.

“When an emergency strikes, it’s critical that Americans are able to use 911 to reach those who can help. The CenturyLink service outage is therefore completely unacceptable, and its breadth and duration are particularly troubling. I’ve directed the Public Safety and Homeland Security Bureau to immediately launch an investigation into the cause and impact of this outage. This inquiry will include an examination of the effect that CenturyLink’s outage appears to have had on other providers’ 911 services. I have also spoken with CenturyLink to underscore the urgency of restoring service immediately. We will continue to monitor this situation closely to ensure that consumers’ access to 911 is restored as quickly as possible.”