GLENWOOD, Iowa - Christi and Nelson Leidel own a $329,000 house that isn't safe to call home.Nelson Leidel circles the growing area of sunken land at the back of his property in Mills County's Loess Hills. The movement of the soft ground under his house caused the foundation to shift, leaving the home uninhabitable for Leidel and his wife, Christi.A close look would show the house's foundation has shifted, opening cracks and buckling floors. A first-floor bay window sags. A bathroom wall bows. Large chunks of the backyard continue to slough off into the creek bed behind their lot.In November, federal officials determined that the four-year-old house was unsafe for the Leidels to occupy. Yard signs caution neighbors.The problem traces to rain draining from a subdivision into the house's backyard, which sits at the bottom of a steep slope in an area of western Iowa known for its bluffs and unusually soft ground.The uninhabitable house has left the Leidels wi