Earthquake Preparedness in Seattle: A Resident's Checklist

Published May 3, 2026 · 13 minute read

If you live in Seattle, there is a non-trivial chance you will experience a major earthquake during your lifetime here. Not maybe — actually. The U.S. Geological Survey places the probability of a magnitude-9 or greater Cascadia Subduction Zone earthquake at roughly 14 percent over the next fifty years, with a separate Seattle Fault risk on top of that. Both have happened before. Both will happen again. The point of this article is not to alarm you. It is to give you a concrete, two-hour preparation list you can actually finish this weekend, and to explain the geology clearly enough that you can prioritize the parts that matter most for your specific situation.

Two earthquakes, not one

Seattle sits at the intersection of two distinct seismic hazards, and the preparation that helps with one is largely the same as the preparation that helps with the other, but the events themselves would feel and behave differently.

The Cascadia Subduction Zone is a 700-mile-long fault offshore where the Juan de Fuca plate slides under the North American plate. When it ruptures fully, it produces a megathrust earthquake of magnitude 8.7 to 9.2. The last full rupture was on January 26, 1700. Geological evidence shows roughly 19 such events over the past 10,000 years, with average intervals of about 240 years and a range of roughly 200 to 800 years. We are inside the statistical window. A full Cascadia event would shake Seattle for three to five minutes — long enough that anyone caught outside near a tall building or in an unreinforced masonry structure would have to make difficult decisions in the middle of the shaking. It would also generate a tsunami affecting the Washington and Oregon coasts, though Seattle itself is shielded from open-ocean tsunamis by the Strait of Juan de Fuca.

The Seattle Fault runs east-west through the city, passing roughly under SODO, the I-90 corridor, Mercer Island, and Bellevue. It last ruptured around 900 to 930 AD in an event estimated at magnitude 7.0 to 7.5. That event raised parts of Bainbridge Island, dropped parts of West Seattle, and produced a tsunami in Puget Sound large enough to leave geological evidence in lake sediments. A magnitude 7+ Seattle Fault event would do tremendous damage to downtown, the SODO industrial district, and the older brick neighborhoods of Pioneer Square and the Chinatown-International District. Shaking duration would be shorter — perhaps 30 to 60 seconds — but the intensity at the surface, especially in soft-sediment areas, would be severe.

For the purposes of preparing your household, the differences mostly don't matter. You want supplies, you want a plan, and you want to have done the boring physical work of securing your home before the shaking starts.

The two-hour weekend list

This is the version of the preparedness checklist that you can actually finish in an afternoon. Everything below can be done by one or two adults with no special tools or expertise.

Hour one: secure the building you live in

Anchor your water heater. Most water heaters in Seattle are not adequately strapped. A loose water heater tips over in moderate shaking, ruptures the gas line, and starts a post-earthquake fire. Two metal straps and four lag bolts into the studs takes about 20 minutes. Hardware store kits are around $15.
Strap your tallest furniture. Bookshelves, dressers, china hutches, and free-standing wardrobes are the most common sources of crush injuries in residential earthquakes. Furniture anchor straps (the kind sold for child-proofing) work fine. Anchor to wall studs, not drywall.
Move heavy items off high shelves. Anything heavy enough to hurt you if it falls from above shoulder height — get it lower. Books are usually fine. Cast iron is not.
Know where your gas shutoff is. Find the meter on the outside of your building. Identify the shutoff valve and the wrench you would use to turn it. Buy a $5 dedicated wrench and zip-tie it next to the valve. Do not turn the gas off pre-emptively — you cannot easily turn it back on yourself and a gas-company restoration takes days after a major event.
Know where your water shutoff is. Usually at the front of the property near the sidewalk, sometimes in a basement utility room. Make sure you can operate it.

Hour two: assemble the kit

Water: One gallon per person per day, for at least three days. Seven days is much better if you can store it. Tap water in clean two-liter soda bottles is fine and almost free.
Food: Three to seven days of food that requires no refrigeration and minimal preparation. Canned goods, peanut butter, dried fruit, granola bars, instant oatmeal. A manual can opener.
Medications: A seven-day rotating supply of any prescription medications, kept fresh.
Flashlights: At least one per person, with spare batteries. Headlamps are better than handheld for the first few days.
Hand-crank or battery radio: Power and internet will be down. A radio is how you will learn whether tap water is safe to drink and where shelters are open.
First-aid kit: A basic one is fine. Add a pair of work gloves and an N95 mask — you may need to move debris.
Cash: Small bills. ATMs and card readers may not work for days.
Sturdy shoes near your bed: If a major earthquake hits at night, you will need to move through broken glass to get out of your bedroom. Keep closed-toe shoes within arm's reach.
A printed list of important phone numbers: Your phone may not work and you may not have it. Family contacts, an out-of-state relative as a check-in coordinator (because in-region calls jam first), your insurance company.

Store the kit somewhere accessible but unlikely to be blocked by debris — a hall closet, the trunk of your car, a garden shed. Not under the bed (which may be unreachable) and not in the back of a deep storage closet (which may be blocked).

What to do during the shaking

The standard advice is Drop, Cover, and Hold On. Drop to the floor before the earthquake drops you. Cover your head and neck (under a sturdy table is best, or against an interior wall if no table is available). Hold on to whatever you are using for cover so it does not slide away from you. Do not run outside during the shaking — falling glass and exterior brick veneer from older Seattle buildings cause more injuries than collapsed interior structures.

If you are in bed when shaking starts, stay there. Pull a pillow over your head and face. Beds are sturdier than people give them credit for and the trip from bed to a "safer" location is one of the riskiest you can make during shaking.

If you are driving, pull over as soon as you safely can, away from overpasses, signs, power lines, and bridges. Stop, set the parking brake, stay in the car until the shaking stops. Do not park under a freeway overpass — these are some of the most likely failure points.

If you are outdoors, move away from buildings, power lines, and trees. Get to an open area and crouch. Most outdoor injuries are from falling exterior elements, not from the ground itself.

The first 72 hours

Seattle Fire and SPD will be overwhelmed during the first 72 hours after a major earthquake. You should plan to be self-sufficient for that long, possibly longer. Specifically:

Do not call 911 unless you have a life-threatening emergency. Calling to ask whether tap water is safe will jam the system for someone who is buried in a collapsed building. Use the radio for general information.
Check on neighbors. Most rescues in the first hours after a major earthquake are made by neighbors and bystanders, not by professional responders. If you have an elderly neighbor who lives alone, that is your first stop after confirming your own household is safe.
Do not drive unless necessary. Roads will be cluttered with debris and downed power lines. Bridges may be unsafe. Traffic signals will be down. Walking is faster and safer for short distances.
Do not light open flames until you have confirmed there is no gas leak. The smell of gas plus an open flame is the most common cause of post-earthquake fires.
Boil any tap water before drinking, until water utilities announce it is safe. Seattle Public Utilities will make announcements over radio.

Apartment dwellers

If you live in an apartment, especially in an older building, there are a few additional considerations. The biggest is: do you know what your building is made of? Unreinforced masonry buildings (URMs) — typically pre-1945 brick or stone construction — are the highest-risk residential buildings in Seattle. The city maintains a public list of identified URMs at seattle.gov. If your building is on the list, it does not mean it will collapse, but it does mean you should prioritize having a kit, identifying multiple exits, and being able to evacuate quickly.

Newer mid- and high-rise buildings in Seattle are built to current seismic codes, which are strong. They will sway considerably during a major earthquake but they are designed to remain standing. The biggest risks in modern apartment buildings are unsecured furniture and broken glass, not structural failure.

What this site can and cannot do during an event

Seattle Breaking depends on the City of Seattle's open-data feeds. During a major earthquake, those feeds may go offline for days. The CAD system itself may be overwhelmed and may stop publishing exports. Our backend may lose power or internet connectivity. In the immediate aftermath of a major event, do not rely on this site for situational awareness. Rely on your radio, your neighbors, and your own eyes.

Once the immediate emergency is over and the public datasets resume, the site will return to operation. We have no special authority during emergencies and no special ability to call in resources on your behalf.

The honest summary

You will not be able to prevent a major earthquake. You can, with a few hours of work, dramatically reduce the chance that one seriously injures you or your family. Strap your water heater this weekend. Buy a case of water. Put a flashlight on your nightstand. That is most of the value. The rest is incremental.

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