A spokesman for the Hawaii Emergency Management Agency said a malfunctioning emergency warning siren that sounded in error Saturday night was caused by an amplifier in the siren apparatus that had short-circuited.
According to HI-EMA spokesman Adam Weintraub, the siren that sounded in error at about 8:30 p.m. is located near the intersection of Banyan Drive and Kamehameha Avenue in Hilo.
Weintraub said Monday a caller notified the county almost immediately that the siren was sounding at about 8:30 p.m., “but the caller wasn’t clear on whether it was just one siren or multiple sirens, and could not provide a specific location.”
According to Weintraub, the county notified HI-EMA’s operations center at Diamond Head crater in Honolulu within a minute of being notified of the malfunctioning siren, “and verified that there was no emergency that had prompted the activation, which confirmed the siren should not have been sounding.” He said HI-EMA sent a signal to deactivate the siren, “but it’s unclear if that was successful.”
“Either the county or HI-EMA can activate sirens, but in this case, neither one did so,” Weintraub said Monday. “Meanwhile, county personnel were gathering information that narrowed down the location of the runaway siren to the area near Banyan and Kamehameha. They dispatched workers physically disconnected the unit from the power supply.
“Because there was an unknown lag between the time the siren started sounding and the time Hawaii County was notified, we don’t have an exact time for how long it was going off, but it was roughly five minutes,” Weintraub added. “… Given the unusual circumstances, and the time it took to verify there was no emergency and pin down the location, that’s about as fast a response time as possible.”
According to Weintraub, Hawaii County Civil Defense issued a radio message and Everbridge alert confirming there was no emergency, by about 8:45 p.m., and HI-EMA issued a similar announcement via Twitter at 8:48 p.m., following up with a news release containing more details at 9:49 p.m.
“Coverage areas vary based on location and conditions, but in general the sirens in Hawaii’s network can be heard within a radius of at least a half-mile from the horn,” he said. “It’s unclear in this case whether the siren was fully activated or if only some of the circuitry was affected, which could have reduced the radius.”
The last time a mechanical malfunction of an emergency siren caused a siren to sound in error was at about 7:15 a.m. on Dec. 6, 2017, when a siren in the Panaewa area of Hilo started blaring.
According to a since retired Civil Defense spokeswoman, Civil Defense transmitted a cancel tone to turn the siren off within a few minutes of being notified by a resident of the malfunction.
The statewide test of emergency alert sirens is scheduled for 11:45 a.m. today.
“We know the siren network serves a vital function in protecting the people and property of Hawaii, and we appreciate the close partnership with Hawaii County Civil Defense that helped to quickly resolve the incident Saturday night,” Weintraub said. “Their personnel immediately jumped into action and were able to inform the public very quickly that there was no immediate threat.”
Email John Burnett at jburnett@hawaiitribune-herald.com.