Pa. 911 system restored; tractor-trailer crash blew fuse
Callers got busy signals after dispatch went down, and officials say a voltage spike tripped the circuit breakers in the uninterruptible power supply
ALLEGHENY COUNTY, Pa. — A tractor-trailer crashing into a telephone pole might have caused an emergency radio communication failure in Allegheny County on Thursday.
The vehicle hit the pole in the 2900 block of Railroad Street in the Strip District at 6:56 a.m., Pittsburgh Public Safety Director Mike Huss said. By 7 a.m., an alarm informed shift commanders at the 911 center that radio dispatch channels out of the county's facility on Railroad were disconnected, said Alvin Henderson, chief of the county's Department of Emergency Services.
“That's what seems to have initiated this whole thing,” Huss said. The uninterruptible power supply (UPS) system, which makes sure sensitive radio equipment isn't overloaded with electricity, received either an overcurrent or voltage spike that tripped all of its circuit breakers and blew internal fuses, Henderson said.