The 6.9 magnitude earthquake that struck Eureka, California on Sunday may be over, but scientists say that Northern California will remain under threat for many years to come. The Cascadia subduction zone in the Pacific Northwest continues to be a hot spot of geological activity, and may some day cause great damage to the region.

Sunday wasn’t the first time a sizable earthquake erupted out of Cascadia. Three hundred years ago, according to a report by the United States Geological Survey, a 9.0 earthquake and tsunami tore through the pacific, causing damage from the American Pacific Northwest to Japan. The worst part is, it could easily happen again.

According to a 2013 report by the Federal Emergency Management Agency, if a 9.0 earthquake struck the Pacific Northwest today, the event could result in over 10,000 deaths and 70 billion dollars of losses. Infrastructure would be devastated and countless people would be forced to become refugees.

“Katrina was a worst case scenario for hurricanes in the gulf. And a Cascadia would be the worst case scenario for tsunamis on the West Coast,” Paul Whitmore, director of the National Tsunami Warning Center in Alaska, told the LA Times. Municipalities across the area continue to prepare for the inevitable danger by creating shelters, safe havens, and vertical evacuation centers out of existing buildings.

“We dodged a bullet,” Lt. Steve Knight of the Humboldt County Sheriff’s Office told the Times-Standard, “This very easily could have been a catastrophe that could have caused a lot of damage.” It will remain to be seen if the 6.9 earthquake of Sunday will serve as a wake up call for emergency management services in the area. Earthquakes continue to erupt from the Cascadia subduction zone, including a 5.2 earthquake 212 kilometers West South West of Gold Beach, Oregon, according to the U.S.G.S. No earthquakes larger than Sunday’s 6.9 earthquake have been yet reported.

Image via United States Geological Survey