San Francisco's Outdoor Public Warning System, which sounds off during a weekly test every Tuesday at noon, will be going on a two-year hiatus, the city's Department of Emergency Management said.
The system, which is made of 119 sirens located throughout the city, is used to alert people about emergencies like a tsunami, a contaminated water supply or a radiological attack.
The alarm, however, will be heard for the last time next Tuesday at noon before the system temporarily shuts down for upgrades.
The upgrades will be installed over the next two years and will cost about $2.5 million, improving the system's reliability and security.
"The Outdoor Public Warning System has stood guard in San Francisco since World War II. As we temporarily relieve the antiquated sirens from their watch for much needed upgrades, San Franciscans can be confident that the city will continue to provide timely alerts and warnings," Mary Ellen Carroll, SFDEM's executive director, said in a statement.
The last upgrades to the system were made back in 2005.
As the new upgrades are being installed, the city will continue to rely on other alert and warning tools already in place, like AlertSF, the Emergency Alert System and Wireless Emergency Alerts, as well as social media.
During the upgrades, residents and visitors are being encouraged to sign up for AlertSF, the city's emergency text message system, by texting their zip code to 888-777 or by visiting www.alertsf.org.