When you lose an item due to an accident, theft, or natural disaster (which the IRS calls a "casualty loss"), you may be able to take a tax deduction for the value of the property that is not covered by your insurance. The lost or damaged item can be business property, investment property, or personal property. 

The cost basis is the amount you paid plus additions minus any depreciation claimed.  If you had numerous items, include a  summary of the property lost.  

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