On Thursday night, CenturyLink experienced an outage which affected the 911 systems in Washington.

But this isn't the first time CenturyLink has experienced an outage which affected emergency systems.

CenturyLink has been fined in the past after an outage crippled the 911 system in Washington state.

In 2014, according to The Seattle Times, a six-hour outage led to more than 5,800 failed 911 calls.

In one case, a woman tried calling 911 37 times after a burglar got into her home.

In another case, a domestic violence victim had to flag down police because she couldn't get through.

The FCC fined CenturyLink $16 million over that outage and state regulators tacked on another $2 million

The FCC is investigating this latest nationwide outage that led to 911 problems, including issues in Clark County, Washington. 

RELATED | Startled Oregonians get 911 outage alert from Clark County

FCC chairman Ajit Pai said not being to call emergency services is "completely unacceptable" and is "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," said Pai.

Century Link has been tweeting updates throughout the day.

In one tweet the company told people to "use their wireless phones to call 911 or drive to the nearest fire station..." 

However, in Clark County, people could not get through to 911 on their cell phones or landlines because of the outage.