What if we have an Earthquake and I'm in a store?

There are lots of bottles and breakables and no where to go? Just duck and cover? I am the first istant at a small store and was wondering what to tell my customers. I live in IL and we've just had 16 quakes in 3 days. I'm sure you all have heard about it. Luckily no damage yet but all the talk of "the BIG ONE" has come back and it's something I should worry about since I'm there a lot.