This year Mill Valley was one of the first California cities to install this new siren system, called Long Range Acoustic Device, or LRAD. Mill Valley’s previous, 2-decades-old siren emitted a generic alarm for all emergencies. The new system can blare messages with specific instructions about what to do or where to go. It has battery backup that can survive PG&E power shut-offs and backup activation methods for when cell phone networks fail.
Long before text messages, Bay Area residents learned of impending disasters via sirens. But worsening wildfires, power shut-offs and wireless outages have raised the profile of alert systems.
During the 2017 Tubbs Fire, Sonoma County officials faced criticism for failing to send alerts until residents had to flee for their lives. A year later, Butte County didn’t activate a phone-takeover emergency system during the Camp Fire, the state’s deadliest. And this year, with mass electrical shut-offs during the Kincade Fire, some cell towers also went down, especially in Marin.
Faced with these communication problems, some local governments are improving their sirens.