If the fault has enough stress built up to cause a 5.0+...then let it get it done with. I'd rather have a couple 5.0s instead of a 6.0 or 7.0 occur on a fault line that lies in the Metro area. A metro area where, i'm guessing, the building codes are setup to ensure structures can resist such a tremor. Granted they do have to withstand our normal weather, so that may help. The only structure that immediately pops into mind though would probably be the Crosstown. However, it may take more than 5.0 or so to bring that down.