Have you ever found yourself trapped during a partial collapse or deep search for someone? For occasions such as this, I like to carry a Personal Escape Tool (PET). You're only limited by your imagination as to what you want to carry, even if there's limited space in your bunker. My tools of choice are lineman's pliers and an item that looks like a chainsaw chain but is designed to be thrown around a piece of wood and moved back and forth to cut through the offending piece of lumber.

One thing to keep in mind, however: Make sure that the piece of lumber is not weight bearing ... to the best of your knowledge based on the information available at the time, that is. Also, you'll need to make sure you have enough room to at least get the tool out of your pocket, assemble it and use it.