California earthquake puts early warning system to the test


              Brenda López Alvarado, left, and Celia Magdaleno walk to their homes after collecting water from their neighbor's pool following an earthquake in Rio Dell, Calif., Wednesday, Dec. 21, 2022. Water service has not return to the city. (AP Photo/Godofredo A. Vásquez)
            
              Celia Magdaleno turns on her gas stove to boil water before giving her husband a bath, following an earthquake in Rio Dell, Calif., Wednesday, Dec. 21, 2022. Magdaleno's husband is undergoing dialysis treatment and said is crucial for him to be clean before receiving treatment to avoid infections. (AP Photo/Godofredo A. Vásquez)
            
              Celia Magdaleno, 67, collects water from her neighbor's pool to use for her toilet since water service has yet to resume following an earthquake in Rio Dell, Calif., Wednesday, Dec. 21, 2022. (AP Photo/Godofredo A. Vásquez)
            
              FILE - Dr. Lucy Jones, senior advisor for risk reduction for the U.S. Geological Survey, describes how an early warning system would provide advance warning of an earthquake, at a news conference in the Seismological Laboratory at the California Institute of Technology in Pasadena, Calif., on Jan. 28, 2014.  Seconds before a magnitude 6.4 earthquake jolted the Northern California coast, an alert sent by phone warned 3 million people to "Drop, cover, hold on." The event marked the greatest test yet to an earthquake warning system launched three years ago. (AP Photo/Reed Saxon, File)
            
              FILE - A mobile phone customer looks at an earthquake warning application on an iPhone in Los Angeles on  Jan. 3, 2019. Seconds before a magnitude 6.4 earthquake jolted the Northern California coast, an alert sent by phone warned 3 million people to "Drop, cover, hold on." The event marked the greatest test yet to an earthquake warning system launched three years ago. (AP Photo/Richard Vogel, File)
California earthquake puts early warning system to the test