Thursday at 10:20 a.m. is the start time of this year’s Great Shakeout Earthquake Exercise.

An earthquake on the Cascadia fault line or even a large inland earthquake could be catastrophic and something for which everyone in this region should prepare, said Chuck Wallace, deputy director of Grays Harbor County Emergency Management.

There will be a full three-minute emergency siren sounded on Thursday as part of the 20-minute exercise. The siren system is operated statewide.

Grays Harbor County buildings will be shut down for this 20-minute exercise. Employees of other local governments as well as students and staff of area schools will “drop, cover and hold on” or evacuate buildings as part of the exercise so people traveling at that time Thursday should use caution, Wallace said.

Wallace asks that area businesses also participate. A lot of businesses have people on the road or working off site and it’s important everyone be accounted for after such an event.

“Everyone should know where to go and what to do,” Wallace explained.