It’s being called the largest exercise of any kind in Washington state history, and it’s all about getting ready for what scientists say is coming: a magnitude 9 earthquake and ensuing tsunami. For decades, evidence has built about the impact of what a magnitude 9 earthquake will have along the Cascadia Subduction Zone, a fault line that runs from Cape Mendicino, California, up past Oregon, Washington and along the western shore of Vancouver Island, British Columbia, Canada.

In total, the exercise involves multiple states, Washington, Oregon and the Canadian province of British Columbia. Some 20,000 people will be involved, from civilian first responders to active duty elements of the U.S. Army, Navy, and Coast Guard. And the idea, says Lt. Col. Clay Braun of the Washington Military Department, is to test the response as much as they can. To find the holes and patch them for the time when the real earthquake hits. READ MORE