If a property insurance policy covers “collapse” without specially defining the word, but also excludes coverage of settling, cracking, shrinkage or expansion, the policy does not cover mere “substantial impairment of structural integrity.”  Here, a gas station had to excavate and repair an underground gas storage tank after its outer fiberglass shell split on the boulder that the tank had improperly been installed on top of, but the inner steel lining of the tank was still intact.  At most, the fact that the tank no longer met state environmental regulations and could no longer be used until repaired meant that there had been a substantial impairment of its structural integrity, but not a collapse.