SPOKANE, Wash. -- Local experts say Washington state's biggest threat is an earthquake or wildfire. But, do you know what to do in the event of a nuclear attack?

The Department of Homeland Security said what you should do if there is a nuclear attack depends on where you are. If you are outside, you should lie face down on the ground and protect any exposed skin. You should also grab some sort of cloth and cover your mouth and nose to filter particulates in the air.

While at one point there were hundreds of fallout shelters in Spokane, those shelters are no longer in use or serve other purposes.

If you are inside, or sheltering-in-place, you should go as far below ground as possible and stay inside until authorities say it is safe.

Department of Homeland Security officials said brick or concrete buildings provide the best shielding from radiation in the fall out of a nuclear attack. Exposure to radiation is reduced by 50 percent inside a one-story building and by about 90 percent a level below ground.

For those advised to evacuate you should listen for evacuation routes, temporary shelters and procedures to follow.