A magnitude 4.6 earthquake rattled the Bay Area early Thursday morning, centered in the Santa Cruz Mountains. Buildings swayed. Dishes clinked. And then — almost immediately — everyone went back to whatever they were doing.

This is peak San Francisco. We live on a network of fault lines capable of producing genuinely catastrophic events, and our collective response to a moderate quake is to post a meme and move on. There's something admirable about that nonchalance. There's also something a little insane.

Here's the thing: a 4.6 isn't nothing. It's not The Big One, but it's a solid reminder that The Big One is always on the table. And that should prompt a pretty basic question — is the city actually ready?

The answer, if you've been paying attention, is kind of. San Francisco has spent years and considerable taxpayer money on seismic retrofit programs and emergency preparedness plans. Some of that spending has been smart and necessary. Some of it has disappeared into the same bureaucratic black hole where all city dollars go to die. The Soft Story retrofit program, for instance, has made real progress on vulnerable multi-unit buildings, but timelines have dragged and enforcement has been inconsistent.

Meanwhile, city infrastructure — our aging water mains, Muni tunnels, and emergency response systems — remains a mixed bag of genuinely upgraded and dangerously deferred maintenance. Every earthquake that isn't a disaster is a free pass we might not keep getting.

So yeah, laugh at the quake. Post your "did anyone else feel that?" tweet. But maybe also check your earthquake kit, make sure your renter's insurance covers seismic events (spoiler: it probably doesn't by default), and ask your supervisors what exactly the city's been doing with your emergency preparedness dollars.

Because the Bay Area shrugging at earthquakes is funny right up until it isn't.