Human error by a third-party vendor caused an hourlong disruption to Minnesota's 911 emergency call system earlier this month, state officials said Wednesday.
The widespread outage, which also affected 911 calls in North Carolina and North Dakota, began at 3:47 p.m. on Aug. 1 and was resolved by 4:52 p.m., according to information provided by Century Link, which provides 911 services in Minnesota.
An employee with one of the company's vendors — West Safety Services — made a mistake while making a network configuration change. That triggered an outage that disrupted emergency lines to first responders in cities, county sheriff's offices and at the Minneapolis-St. Paul International Airport.
Dozens of local public safety agencies immediately posted alternative emergency numbers on social media.
CenturyLink reported that 693 calls to more than 50 Minnesota 911 dispatch centers were not routed during the outage. About 350 calls were successfully routed to dispatch centers through a redundant router.
State officials previously said that there were no serious incidents reported as a result of the outage.
CenturyLink said West Safety Services has stopped work on its network through the end of August while it reviews the situation.
"They are also looking into changing processes and procedures along with enhancing software and safety mechanisms to prevent future errors from occurring," state officials said in a written statement.
The Federal Communications Commission, which was notified of the disruption, is expected to conduct an independent investigation, which could result in a fine, state officials previously said. CenturyLink was penalized $16 million for a 2014 outage.
The state is in the second year of a five-year, $29.5 million contract with CenturyLink.