On Monday around 6:30 p.m., a magnitude 3.9 earthquake struck the Bay Area, causing delays to Muni and BART and disrupting the peaceful dinner hour.

While earthquakes are commonplace in the region, they’re a chilling reminder of the looming threat of natural disaster. In the next 30 years, the Bay Area has a 72% chance of experiencing a magnitude 6.7 quake and a chilling 20% chance of experiencing a catastrophic 7.5 magnitude earthquake.

The threat is compounded by “soft-story” buildings — structures that lack a strong first story — throughout the Bay region. They experience especially high collapse rates during large earthquakes.

By and large, the region has taken these threats seriously. Along with passing increased regulations for potentially hazardous buildings in 2014, the city of Berkeley created a soft-story program for retrofitting unstable buildings. The program boasts an 85% success rate, and under the Property Assessed Clean Energy financing program, property owners can easily find loans for seismic retrofits. Berkeley also offers retrofitting grants for soft-story building owners. The surrounding cities of San Francisco and Oakland also both mandate seismic retrofits for soft-story buildings.

However, according to a U.S. Geological Survey report, 39 of San Francisco’s top high rises are extremely vulnerable to a large quake, including the cluster of buildings at the Embarcadero Center, the Pacific Gas & Electric Building, the Transamerica Pyramid, the Hilton San Francisco hotel and the San Francisco Marriott. Lives are at risk every day that passes without seismic retrofitting.

Unfortunately, seismic retrofitting alone might not be enough to protect Bay Area residents.

For example, only 10% of Californians own earthquake insurance, and it’s excluded from standard homeowner and renters’ insurance plans. If a magnitude 7.1 earthquake were to rock the Bay Area, tens of billions of dollars in damages would fall on the shoulders of uninsured residents. In areas highly susceptible to quakes, local officials must educate the public about earthquake insurance and lobby insurance companies to include earthquake coverage in their standard plans.

Residents in the Bay Area region must also be proactive in protecting their own personal safety — establishing a preparedness plan with housemates and community members and collecting an earthquake kit is a good place to start. Downloading the MyShake app can help researchers study, analyze and predict future quakes.

Earthquakes care little for the human-made borders between Berkeley, Oakland and San Francisco. All residents of the Bay Area — no matter in which city they reside — should benefit from the highest level of earthquake preparedness. A large number of buildings are unsafe, few Californians have access to earthquake insurance and not every household has an individual emergency plan. While Berkeley has made serious strides with its retrofitting programs and San Francisco and Oakland have followed suit, complacency should be avoided.

Proactive measures taken today might save lives tomorrow.