The west coast could face disasters at any moment that could kill thousands of people and forever change the lives of millions more, experts say.

The HayWired Scenario is a detailed look at the cascading calamities that will happen when a major earthquake strikes the Bay Area, including the possibility of widespread power-outages that will strand elevators — possibly for weeks

The disaster remains theoretical for now. But the United States Geological Survey estimates a 51% chance that a quake as big as the one described in HayWired will happen in the region within three decades.

It’s one of several West Coast disasters so likely that researchers have put together painstakingly detailed scenarios in an attempt to prepare.

Depending on the scenario, thousands of people are expected to die. Hundreds of thousands more could be left without shelter. And those impacts will be disproportionately felt.

Whether the next disaster to strike the West Coast is a flood, an earthquake or something else, scenario experts warn that the impacts will reverberate for years or longer.

There are many disaster preparedness precautions that are inexpensive and will help in a range of emergency situations. For now, policymakers hold the real power in how prepared society will be for the next disaster.