"Perhaps nowhere is more vulnerable than Ocean Shores... the tsunami that could accompany a 9.0 rupture would wash over all of it. People could try driving out..."

"... but officials expect roads to be buckled and sunken, or covered in power lines, trees and debris. The expected subduction would cause the entire area to abruptly sink up to seven feet; the shaking could cause liquefaction of sandy soils before the tsunami reached shore. People could try running to high ground outside of town, but Ocean Shores sits on a six-mile-long peninsula. Those who live toward the southern end would be about eight miles away from high ground. Depending on their location, residents might have only 10 minutes after the shaking stopped before the wave started washing over them.... The best option may be to get on a rooftop or to climb a tree.... Dozens of other waterfront communities are also at risk.... To improve the chances of survival, officials in Washington State have proposed a network of 58 vertical evacuation structures along the outer coast and advised considering dozens of others. They could provide 22,000 people with an option for escape, although thousands of others would remain out of range. Each structure could cost about $3 million. Vertical evacuation structures have been embraced in Japan for years, in the form of platforms, towers and artificial berms..."

From "The Tsunami Could Kill Thousands. Can They Build An Escape? A major quake in the Pacific Northwest, expected sooner or later, will most likely create waves big enough to wipe out entire towns. Evacuation towers may be the only hope, if they ever get built" (NYT).