A prefabricated storm shelters that can be easily repositioned and assembled while providing safe, secure shelter before, during and after a catastrophic event are described, as well as a method to mfr. The analog voice bridge includes two codecs that are each coupled to a secure network domain and to each other through an analog voice line. The predecoding circuit predecodes address signals. Similarly, the amount of area required to implement such a receiver in an integrated circuit is advantageously reduced. A portion of said center tube exits said tank at said top aperture.