Is it mandatory that owner must report fire loss on his rental property to IRS?

[Ihatedoingtax]

Is it mandatory that owner must report fire loss on his rental property to IRS?

If yes, how many forms do I need to report? What are they?

[MaryK4]

If you are asking if you are required to claim a Property and Casualty Loss (see About Casualty Deduction for Federal Income Tax) you do not have to claim it.  If your insurance covers most of the costs it may not make a difference, but in some cases it can help. 

If you choose not to use the casualty loss, and you pay for any repairs you may be able to deduct or depreciation assets.  In addition, if you sell the property for less because of the condition, you may have less gain on the sale.  

[Mike9241]

if you have insurance that covers any part of the loss, the IRS position is that any out of pocket amounts paid 

for the amount covered are not deductible nor capitalizable and thus depreciable. 

if you choose to file an insurance claim then any loss or gain is reported through form 4684 section B