Built on sand.
Built by SALT WATER.
Salt seeps into the porous concrete over time and the rebar is destroyed....................
26 But everyone who hears these words of mine and does not put them into practice is like a foolish man who built his house on sand. 27 The rain came down, the streams rose, and the winds blew and beat against that house, and it fell with a great crash.”
Matthew 7:26-27