Building demolished - is it capital loss?

ProgTick (N/A) (100 Points)

19 April 2012  

If a building is completely destroyed/demolished (not by the owner!) by accident or vandalism, how to claim loss for it in taxes? If it was built in 1980's, will it be long term capital loss? 

Do I take cost of the building as of the year constructed (assume 1981) and multiply it with indexation thing of that year? Or do I take valuation of the building as of the current year and show the loss as that?