Scheduled Emergency Siren Test Sounds Following Unscheduled Activity

Following two unscheduled activations of San Francisco’s outdoor emergency siren system over the weekend, the regularly scheduled emergency system test that occurs at noon each Tuesday will commence as planned today, according to a spokesman for the city’s Department of Emergency Management.

The 112 sirens that make up the emergency system, located on poles and on top of buildings throughout all neighborhoods in San Francisco, Treasure Island and Yerba Buena Island, are designed to alert city residents and visitors about possible danger, department spokesman Francis Zamora said.

The system allows for specific emergency announcements to be broadcast over any and all of the speakers to alert residents about emergencies such as earthquakes or tsunamis.

Alarms sounded unexpectedly around 11 p.m. Saturday in neighborhoods including Bernal Heights, Noe Valley, Hunters Point, the Bayview and Civic Center, among other areas, despite no actual emergency, Zamora said.

Alarms around the city went off again around 5 a.m. Sunday, he said.

The cause of the siren activation is under review and the system’s hardware and software are being examined, according to Zamora.

The vendor, Acoustic Technology Inc., has also been asked to review the notification system, Zamora said.

During the weekly Tuesday test, the sirens emit a 15-second alert tone, similar to the siren sounded by emergency vehicles, Zamora said.

In the event of an emergency, the 15-second alert will sound repeatedly for 5 minutes.

Several people called 911 to report the sirens over the weekend and dispatch centers were notified about the alarms going off.

In the event of a real emergency, the city will also utilize its text and email alert system that people can register for at

Anyone who hears the siren at a time other than its regular test on Tuesday at noon are advised to stay calm, listen for possible voice announcements, turn on the radio or television for important information provided by city officials and only call 911 if there is a life-threatening emergency.

The city will also post information in an emergency through its social media accounts on Facebook at and, via the Twitter handles @SF_emergency and @SF72org and on Nextdoor at

Hannah Albarazi, Bay City News

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