FILE - In this Oct. 17, 1989 file photo, a California Highway Patrol officer checks the damage to cars that fell when the upper deck of the Bay Bridge collapsed onto the lower deck after the Loma Prieta earthquake in San Francisco. Friday is the 25th anniversary of the Loma Prieta earthquake that killed 63 people, injured almost 3,800 and caused up to $10 billion damage. (AP Photo/George Nikitin, File)
In this Oct. 17, 1989 file photo, a California Highway Patrol officer checks the damage to cars that fell when the upper deck of the Bay Bridge collapsed onto the lower deck after the Loma Prieta earthquake in San Francisco. Friday is the 25th anniversary of the Loma Prieta earthquake that killed 63 people, injured almost 3,800 and caused up to $10 billion damage. (AP Photo/George Nikitin, File)
USGS Geologist Davide Schwartz discusses the history of earthquakes in California from 1906 through today, the individual faults that run through Sonoma County, and where the early warning detection technology stands today:
Construction manager Joe Griego looks at the heavy equipment brought in to support the leaning earthquake damaged historic winery building at Trefethen Family Vineyards Friday, Aug. 29, 2014, in Napa, Calif. Harvest resumed at the winery on Friday in addition to the arrival of crews to shore up the historic building that dates from 1886. The 6.0-earthquake that damaged buildings and left scores of people injured in California’s wine country was the largest temblor to hit the San Francisco Bay Area since the 6.9-magnitude Loma Prieta earthquake in 1989. (AP Photo/Eric Risberg)
Workers sort Pinot Noir grapes with the earthquake damaged historic winery building dating from 1886 in the background at Trefethen Family Vineyards Friday, Aug. 29, 2014, in Napa, Calif. Harvest resumed at the winery on Friday in addition to the arrival of crews to shore up the leaning historic building. The 6.0-earthquake that damaged buildings and left scores of people injured in California’s wine country was the largest temblor to hit the San Francisco Bay Area since the 6.9-magnitude Loma Prieta earthquake in 1989. (AP Photo/Eric Risberg)
In this photo taken Tuesday, Dec. 17, 2013, chief engineer Mike Gay holds up a section of Candlestick Park that was damaged in the 1989 Loma Prieta earthquake after he led a tour of the stadium in San Francisco. Gay has worked at the stadium for 35 years. The San Francisco 49ers are about to play their last game at the stadium they have called home since 1971. Candlestick Park was also the home of the San Francisco Giants from 1960-1999. (AP Photo/Eric Risberg)
FILE : In this file photo taken Oct. 18, 1989, crews demolish a collapsed apartment building in the Marina district following the Loma Prieta earthquake in San Francisco. Friday is the 25th anniversary of the Loma Prieta earthquake that killed 63 people, injured almost 3,800 and caused up to $10 billion damage. (AP Photo/George Nikitin)
