A third-party vendor performing work on a 911 system caused the nearly hourlong service failure across Minnesota on Wednesday, officials said.
The widespread outage, which occurred shortly after 4 p.m. and lasted about 50 minutes, disrupted emergency lines to first responders in cities, county sheriff's offices and at the Minneapolis-St. Paul International Airport. It also affected services in North Dakota and North Carolina, said Dana Wahlberg, director of the Emergency Communication Networks Division for the state Department of Public Safety.
The vendor, West Safety Services, was completing a routine process on their network at the time of the outage, according state officials.
CenturyLink, the state's 911 service provider, and West Safety Services are reviewing the incident to determine what triggered the outage.
"CenturyLink is working with the vendor to understand the root cause and preventive measures," Frank Tutalo, a company spokesperson, said in a statement.
West Safety Services could not be reached for comment Thursday.
In response to the system failure, dozens of local public safety agencies immediately posted alternative emergency numbers on social media. Dispatch centers reported that some calls and texts to 911 during that time were received successfully, while others were not, Wahlberg said.
CenturyLink is required to investigate and explain any outage within 14 business days, though Wahlberg said the company has been asked to accelerate its investigation.