Failures in the power chain left emergency services, at Hartford in the US, having to manually relay calls over the radio. According to a report in a local newspaper, Mike Bruce, the city’s interim director of emergency services telecommunication, said that a “perfect storm” of malfunctioning systems led to the outage.
The root of the problem was attributed to a switch gear component in the building’s electrical system. An Eversource transformer failure knocked out power, causing the backup generators to turn on; the switch gear was supposed to transfer power back to the municipal source from the generators, but the system didn’t work, causing the building to run solely on backup batteries.
At the same time, another system failed because of a broken component that had been discovered earlier in the week during routine maintenance, Bruce explained. The part was on order and technicians were waiting to install it at the time of the outage.
Without the secondary system, the building’s backup batteries eventually failed, leaving the building in the dark. The outage disabled phone lines, certain doors accessible by electronic locks and the computer-aided dispatch system.