PORTLAND, Ore. -- Drop, cover and hold on tight.

Schools and businesses around the country took part in the Great American Shakeout drill on Thursday. The drill is to get people thinking about what they should do, and where they should go if an earthquake hits.

But there's one part of earthquake preparedness that is often overlooked, and we saw just how important it is with Wednesday's gas explosion in Portland.

You should know how to turn off the gas to your home.

Northwest Portland homeowner MJ Christopher knows where her gas meter is on the outside of her home.

But, if she were to ever have to shut it off herself, she may be in trouble.

"I'm not sure I would know how to turn it off in an emergency," she said.

Safety experts say MJ is far from alone. In fact, they say many homeowners don't have that knowledge.

But they point out, in the event of a major earthquake, like the "Big One" scientists say could hit the Pacific Northwest at any time, knowing how to turn off your gas could be life-saving knowledge.

That's because when the earth moves, so will furnaces, water heaters and gas lines. And stopping the flow of gas to them is critical.

"So if there is any type of sever in the line, or your water heater or furnace is damaged, it's not just pouring gas into your home," explained Jason Elton, home performance expert with Enhabit.

Elton says the first step is knowing where your gas meter is. Second, locate the shut off valve on it. Third, know how to shut it off.

You can use your basic crescent wrench and turn it a quarter turn.

Another option is to have a contractor install an emergency shut off valve.

The mechanism will automatically shut off gas coming into your home in the event of a magnitude 5.2 or larger quake.

It's something MJ had done this past spring.

"I just want the peace of mind knowing that if I'm not here, there's something in place to protect my home and my family," she said.

You can get an emergency shut off valve for about $450-500, including installation.

How to find your shutoff valve