San Francisco's outdoor warning system will go silent, for now

A familiar sound heard throughout San Francisco is going away, at least temporarily.    

The city is shutting down its outdoor public warning system on Dec. 11 for at least two years  as the city will spend up to $2.5 million to upgrade the system.

Each week, you can hear the warning sirens all over the city. It's one of the ways the city and county inform the public when there's a serious emergency and its familiar broadcast travels through every area of the city and Treasure Island during testing every Tuesday at noon.

The sound emanates from large speakers like ones mounted on this pole in Laurel Heights. But starting this month, the speakers will go silent for maintenance.

"The system itself hasn't been upgraded since 2005, so it's in need of some upgrades and the amount of time, it could take up to two years, potentially less, but we're expecting up to two years," said Kristin Hogan with the San Francisco Deptment of Emergency Management.

A total of 119 locations are part of the outdoor public warning system and officials say it's more efficient to do all the work at once. During a tsunami or other major emergency, such as contaminated water supply or a radiological attack, the sirens sound.   And residents will still get emergency notifications through alertSF.  

"It's going to be weird that it's not there anymore," said Chris Frakes.

Officials point out there are also other means of getting alerts out.  

"We also use traditional media and social media as well as if the situation... we could ask or first responders to go and help inform residents of something happening in their neighborhood," said Hogan.

But not everyone likes relying on technology, and some eagerly await the return of the sirens.

"Text messages are fine but something when you audibly can hear something going on, it would make you, it's something that would kind of ease the public, to me," said  Anthony Walker.

The last time the system was used during a potential emergency was in 2012 on Treasure Island due to potential water contamination, caused by a water main break.