The U.S. Federal Communications Commission said Thursday it will investigate a problem that prevented some AT&T wireless subscribers from making emergency calls late Wednesday.
There were dozens of reports on social media websites about “911” calls failing to connect.
“Every call to 911 must go through,” FCC Chairman Ajit Pai said in a statement. “I have directed commission staff to track down the root cause of this outage.”
Pai said he spoke to AT&T Chief Executive Officer Randall Stephenson “and stressed the urgent need to restore service and to communicate with first responders, as well as AT&T customers, about the status of operations.”
A person briefed on the matter said a software glitch apparently caused the outage, which lasted at least a few hours.
AT&T spokesman Mike Balmoris said the company was still investigating the cause of the outage.
The National Emergency Number Association, a nonprofit group, said some 911 callers were receiving fast busy signals. The group said the problem shows the “immediate need to transition America’s 911 centers to robust and resilient ‘Next Generation 911’ technology” that “can intelligently route around outages, redirect calls to other regions, or use backup facilities.”
The FCC has previously imposed fines on other carriers that had 911 outages that it deemed preventable, and required steps to prevent further outages.
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Several carriers agreed to settlements after an April 2014 outage that affected 11 million telephone users.
Verizon Communications (VZ) agreed to a $3.4 million fine after a six-hour 911 outage in April 2014 that affected about 750,000 wireless consumers in nine California counties.
CenturyLink agreed to a $16 million settlement in the April 2014 outage and Intrado Communications agreed to pay a $1.4 million fine.
The FCC said the outages at the carriers in April 2014 resulted in 6,600 missed 911 calls “including calls reportedly involving domestic violence, assault, motor vehicle accidents, a heart attack, an overdose, and an intruder breaking into a residence.”
The April 2014 outage was the result of a preventable software coding error at a call management center in Colorado, the FCC said.
In 2015, T Mobile (TMUS) agreed to a $17.5 million settlement after two 911 service outages nationwide in August 2014. The separate but related outages lasted approximately three hours and affected almost all of T-Mobile’s then 50 million customers.