Tools for shutting off gas and water (could be important for after an earthquake). A more robust FAK. A dust filter and goggles and leather gloves (to deal with the mess of demolition style debris). More water. A pry tool. A flashlight and extra batteries. A more robust multi-tool (Leatherman Wave is my preference). A roll of gorilla tape.

That would be a good start anyways. Earthquakes usually require increased material handling and a more hazardous atmosphere present. Most three day packs are generally too anemic anyways.