CINCINNATI -- A "critical failure" stopped 911 calls from reaching the Emergency Communications Center for more than 20 minutes Thursday, according to city officials.
The center received no calls between 10:55 a.m. and 11:18 a.m. Jan. 5, according to a memo from Police Chief Eliot Isaac.
Supervisors at the call center determined "within minutes" that calls were not being routed through their vendor, according to Isaac's memo. Officials believe it was a software malfunction with a Cincinnati Bell subcontractor that prevented 911 calls from being processed from certain areas in Ohio, Kentucky and Indiana.
The system relies on several contingencies that are designed to cope for failures, including rerouting calls to the Hamilton County Communications Center, Isaac wrote. Officials hadn't yet determined if those contingencies worked in this case.
When someone calls 911 from a cellphone, it goes through the cellphone towers to the Cincinnati Bell switch, and then to one of the five 911 call centers in or near Cincinnati, Capt. Jeff Butler previously told WCPO. It typically takes the system just over four seconds to figure out where to send the call, and then however long it takes for the 911 operator to answer, typically just a few more seconds.
Officials wrote that they were working with Cincinnati Bell to ensure it never happens again.