To live in Seattle is to live with potential doom. What draws us to this landscape? Its extraordinary beauty, for one, with the snowcapped peaks of Mount Rainier and Mount Baker acting as bookends to the Cascades skyline. Proximity to water too, deep harbors scoured by ancient glaciers, rushing rivers, numerous lakes. Rare lowlands, flat and fertile, but also the surrounding hills that offer commanding views of "God's Country."

Or is it a preview of the new Pompeii?

Cities, we know, are not invulnerable, even in this century. Port Au Prince is in ruins, New Orleans still recovering and rebuilding from Hurricane Katrina. What makes Seattle beautiful, what draws people here, is also what holds a gun to our heads.

In many ways, it's hard to think of a less secure or more inconvenient place to build a major city. A major earthquake fault cuts across the city, and we're surrounded by others. The geologic records suggest that major catastrophic events have occurred here regularly, from earthquakes to tsunamis to landslides. Mount Rainier is the third most dangerous volcano in America (Mount St. Helens is No. 2, right behind Hawaii's Kilauea, and both Mount Baker and Glacier Peak are in the top 18). An eruption, a cone collapse, lahars and mudflows could wipe out vast areas between Seattle and the mountain and cause tidal waves on Puget Sound or Lake Washington. Who says picture postcards can't kill?

Our settling here hasn't tamed the earth, though we've reshaped it to our whims and needs. We've built dams and levys, both secure and flawed, that work at least as long a nature cooperates. We might have dodged major floods this season not because of sandbags, but El Nino. We scurry around a landscape seemingly designed to defy the urban grid. We've washed away hillsides and filled in tidelands to make more room, but the landscape poses challenges to the infrastructure we build to make it livable. Madison Valley is not truly flood-proof, homes in Greenwood sink as the underlying bog settles, SoDo and the industrial area rests on jiggly fill, and global warming — a slow-moving potential disaster — could challenge our shorelines and water supply.

Disaster is a major theme in our politics, especially as a way to goose gridlocked projects (and with the help of You Tube). Replace the 520 bridge because it might sink in a storm (like the Hood Canal and old Lake Washington floating bridges did) or it might be shaken by a major earthquake (there's a fault that runs right under it). Tear down the Alaskan Way Viaduct and fix the sea wall before they collapse in the next quake. A computer animation of a pancaking Viaduct became a major controversy in last fall's mayoral campaign because of its power to alarm. And let's not forget that Greg Nickels lost because the city was perceived to be unprepared to deal with a relatively minor emergency, a comparatively modest snow storm.

Now, Pompeii's new mayor, Mike McGinn, worries publicly about the urgency of the waterfront seawall replacement project, and wants to move it to the head of the line after apparently receiving an "alarming" briefing from the experts (though the McGinnies pooh-poohed such tactics when the viaduct video was released during the campaign). The waterfront is especially vulnerable: aging infrastructure, quake vulnerability, the age-old risks of water meeting land and man-made structures, providing grist for gribbles. The ground itself is iffy: the Washington Street Boat Launch, where McGinn announced his seawall initiative, is the only place in town I know where there's a historic plaque commemorating the specific contents of the fill dirt beneath your feet, which includes, interestingly, tons of rock from San Francisco's Telegraph Hill. Landmark landfill, who knew?

Politicians frequently use the doom card. It's often responsible, but it also appeals to fear, a strong motivator. It can also offer political safety. If a disaster doesn't happen, you're not wrong, because there's always tomorrow. If it does happen, you've played the prudent seer and can say "I told you so." Cassandras in American politics tend to be disparaged if they complain too much, because we value optimism. But it's worth remembering that Cassandra was right, it was the people who were doomed not to believe.

Realistically, it's impossible to make Seattle safe. We assess risks, we fix what we can afford, we take our chances. It's been a decade since the Nisqually quake put the viaduct replacement on the front burner, and still it stands, somewhat sagging, doing its job while we argue. So far, we've gotten away with ignoring Cassandra, though some have substituted one kind of denial for another. The downtown tunnel advocates downplay the risks and costs of building their alternative, while opponents predict a fiscal and engineering fiasco if we proceed.

And boondoggles are a common kind of man-made disaster because of the politics of them. Those who have studied the problem of massive public projects have learned that the people who give them the go-ahead are politically safe because they are usually long gone when when their pet projects stagger to the finish line under the weight of massive cost overruns and delays. Yet these are quickly forgotten as the public and politicos have already moved on to the next one.

But there's another problem: in a place like Seattle, with so many risks to the man-made environment, everything is threatened. How do you sort out the real risks from the imagined, the politically convenient from the inconvenient? If you cry "safety" too often, people tune it out because they have no sense of priority, or of doable solutions. Chicken Little-ism can breed distrust, complacency, fatalism, boredom.

If we went on a massive infrastructure tear of rebuilding, retrofitting, and mitigating, we still could not protect ourselves completely from the worst nature can throw our way. Nor can we redesign the region to be disaster-safe (or liability-proof) because there are so many things that can happen, sometimes in combination. If you concentrate people into dense urban cores, you put them on shaky ground beneath structures that can topple on their heads; if you continue to sprawl across the landscape, you make it hard to evacuate people from what the mountains and rivers might throw down. And even if catastrophic mudflows or a quake "only" wiped out everything between Mount Rainier and Tacoma, the damage downstream and the ensuing economic calamity to the region would be almost unimaginable. The fact is, something on that scale will happen, someday, some century.

To live here happily, you have to be fatalistic, or in denial. The differential between geologic time and human time is what keeps us sane, and on edge when you think about the risks. A massive tsunami might hit the Pacific coast every 500 years; Nisqually-type quakes occur every 50 years; a massive quake on the Seattle fault might happen every thousand or more years. Mount Rainier cuts loose lahars and flows that reach the lowlands every 500 or 1,000 years. On the former schedule, we're coming due: the government says there's a one-in-seven chance of this happening within an average human life-span. But it's also possible that we could sprout new old-growth forests before anything truly devastating happens. We're borrowing time, but don't know when the note is due.