Check for fires and fire hazzards around your home. Put out any you find with a fire extinguisher or baking soda. Locate your battery-powered radio, tune in to your emergency radio system and listen for advisories. Locate your flashlight, too, if the situation calls for it. Always use a flashlight instead of matches when walking around.
Explosions are possible.
If you haven't already, locate you Disaster Supplies Kit and run an inventory check of your materials. Be sure you have enough water and food to last for at least three days. Keep your supplies safe from aftershocks. Move around carefully and use extreme caution when going inside damaged buildings. Even the mildest of aftershocks can bring down a building with structural damage.