These individuals study End Times prophecy and believe that one of various scenarios might occur in their lifetime. While some Christians (and even people of other religions) believe that the Rapture will follow a period of Tribulation, others believe that the Rapture is imminent and will precede the Tribulation ("Pre-Trib Rapture"). There is a wide range of beliefs and attitudes in this group. They run the gamut from pacifist to armed camp, and from having no food stockpiles (leaving their sustenance up to God's providence) to storing decades' worth of food.
Earthquakes, tornadoes, and hurricanes can cause you to leave your home or even be trapped there. Roads could be blocked due to fallen trees, power lines, or even damaged earth from the natural disaster. Rescue crews can not be in all places at once. You may have to wait it out for quite a while before its over. You won't be able to go to the store or to the corner market.