If you own a home anywhere west of the Cascade Mountains, bolt it to its foundation. The majority of private homes in the timber-rich Pacific Northwest are made of wood—and wooden homes, like trees themselves, are supple enough to withstand even powerful shaking. Those that are bolted to their foundations should fare very well in the Cascadia earthquake. Conversely, those that are not bolted down will jolt off their foundations and collapse, imperilling everything—and everyone—inside them. Securing a home to its foundation generally costs between $2,000 and $6,000—by far the most expensive seismic upgrade facing individuals, but a whole lot less costly than losing the entire house.

Strap down your water heater. A water heater is basically a bomb in your basement: big heavy object, open flame, gas line. If it topples over during an earthquake, it can smash that line and start a fire. Or it can smash the water line and cause a flood. Or it can do both. You can hire a plumber to secure your heater, or do so yourself with a water-heater-strap kit, available at any home-improvement store for around twenty dollars. (And while you’re down in your basement, make sure you know how to turn off your gas and water main. You’ll want to shut off both after the quake—not a good moment to be figuring out how to do so for the first time.)

Redecorate your home with an eye to gravity. Computers, blenders, vases, houseplants, your daughter’s soccer trophies, your TV: everything you are accustomed to thinking of as home décor will be requisitioned as a weapon during the Cascadia earthquake. Your job is to prevent that, and you can do so in a couple of hours and at essentially no cost. Bolt bookshelves and tall furniture to the wall. Move heavy objects from higher shelves to lower ones. Don’t hang pictures, mirrors, shelves, or anything else sharp-edged or heavy above a bed. Install latches on your cabinets. And don’t store booze above waist level. Airborne wine bottles do not do good things to human heads.

Make a plan with your family. No matter when it strikes—though especially if it does so during school and business hours—the earthquake will leave countless people separated from their loved ones. At the same time, it will cut or severely compromise telecommunications systems, making it difficult or impossible to track one another down via phone calls, e-mails, or texts. Ask a friend or relative outside the region to agree to serve as a contact person for your family; if it does become possible to send messages in some form, you’re more likely to get through to someone when their end of the communications systems is functional and the lines aren’t overloaded. Choose a meeting place for your family, remembering that many bridges will be down and many roads impassable. Find out if your city has designated earthquake-gathering areas, where food, water, and first aid will be available; some, like Portland, do. If you have children, learn the earthquake plan at their schools, day-care centers, camps, and after-school activities. If you live across a bridge from where you work or where your children attend school, arrange in advance for a friend to pick them up or meet them at home if the earthquake occurs during school hours and you cannot get there yourself.

Get to know your neighbors. In most disasters, neighbors become the de-facto first responders, since they are already on the scene when calamity strikes. That will be especially true in the Cascadia earthquake, where widespread damage to the infrastructure will make travel difficult for heavy vehicles like fire trucks and ambulances. (Portland could be in particular trouble in this respect because, by a sociopolitical quirk, the majority of the city’s emergency responders live across the Columbia River, in Vancouver, Washington—a short commute on a normal day, but a nearly impossible one after the earthquake, since, at present, no bridges over the Columbia are expected to survive.) Find out which of your neighbors has an elderly relative on a ventilator, which one has a generator, which one has a past as a paramedic. Knowing facts like these about each other can save lives: theirs, or yours. Seattle, Portland, and many other cities have programs to help promote and organize neighborhood meetings and earthquake training.

Keep an earthquake kit in a safe, accessible spot in your home. Unless you’re in the tsunami-inundation zone, you will almost certainly survive even the worst Cascadia earthquake. Which is exactly why you should plan for it: you’re still going to be around afterward, when life gets physically, emotionally, and logistically hairy. You can make things easier—on yourself, your family, your neighbors, and emergency responders—by assembling a decent earthquake kit and storing it in a safe, accessible place. Some things to include:

Emergency-contact information

Copies of important documents (birth certificates, passports, driver’s licenses, wills)

Cash (A.T.M.s won’t work after the quake)

Prescription drugs (these expire, so, as with food, you’ll have to periodically replace them)

Flashlights

Extra batteries

Spare eyeglasses

A whistle (attach one to your key chain, too, in case you wind up trapped somewhere)

Basic first-aid supplies

Warm clothing

Sturdy shoes

Rain gear

Sleeping bags

A tent

You should also store food and water. The conventional wisdom among emergency planners is that every household should have a three-day supply of each on hand (figure a gallon of water per person per day, for drinking as well as washing), but in the Cascadia event that won’t be nearly enough. The more realistic target is a three-week supply, but that’s a daunting amount for those with limited means or limited storage space. My own theory about earthquake preparedness is that the perfect is the enemy of the good: don’t choose to stock nothing because you can’t stock everything. Got money and space to spare? Great: fill a shelf with water and nonperishable foods. Throw in duct tape and a tool kit. Throw in a hand-cranked radio, a water purifier, iodine. Don’t have much money or space? Make a small kit with whatever you can fit and afford. Everything you have, you’ll use; everything you can do for yourself frees up emergency resources for those in even greater need.

If you live in the tsunami zone, know how to get out. Those who live in the inundation zone need to be at least as prepared for the earthquake as everyone else, since the shaking will be stronger in coastal areas than inland. But if you live in the inundation zone, you aren’t bolting your home to its foundation to save it; nearly every building in that zone will be lost. You’re doing so to protect yourself from injury so that you can get out as quickly as possible after the shaking stops. Nor are you building an earthquake kit that you can subsist on for weeks; you’re building one that you can grab and take with you when you leave, so you should focus on the lightweight and the crucial: important documents, medicine, a flashlight. Most important, learn your evacuation routes—from home, from work, from school, from anywhere else you routinely find yourself—and practice walking them, both by day and by night. And when the actual quake hits and you get to high ground, stay there; after the initial wave, others will continue to strike for up to twenty-four hours. One good way to die in a tsunami is to venture back into the inundation zone after the water first recedes, to investigate the damage or look for missing loved ones.