Bay Area communities are marking the exact moment the massive Loma Prieta earthquake hit the region 20 years ago with both reflection and preparation.

San Francisco will culminate a week of earthquake preparedness activities with a recognition ceremony and a moment of silence at 5:04 p.m., the exact time the 6.9-magnitude quake struck the region in 1989.

During this event at the Marina Green, Mayor Gavin Newsom is scheduled to unveil plans for a monument to honor the San Francisco Fire Department for their rescue efforts on Oct. 17, 1989.

In the East Bay, 5:04 p.m. will be marked by emergency sirens sounding in Oakland, Alameda and San Leandro, and on Coast Guard Island. City officials are cautioning residents not to be alarmed by the siren blasts.

Oakland is holding its own remembrance ceremony at 5:04 p.m. The tribute will take place at Cypress Freeway Memorial Park at Mandela Parkway and 14th Street, named for the double-decker stretch of Interstate Highway 880 that collapsed during the earthquake, killing 42 people.

In addition to remembering the earthquake’s victims and the many people who helped with rescue efforts, cities are also using the weekend to advocate disaster preparedness. Oakland held an emergency preparedness fair this afternoon, and on Sunday, other East Bay communities will conduct a major disaster training drill.

The Lamorinda Community Emergency Response Team will simulate disaster animal rescue, sheltering disaster victims and responding to a fire situation.

In addition to today’s Loma Prieta earthquake anniversary, Lamorinda CERT organizers also noted that Tuesday is the 20th anniversary of the massive East Bay Hills fire.

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