I need to recapture depreciation for destroyed house. How do calculated the "depreciation recomputed " for this house? I what number do I put in the box?

The depreciation recapture is referring to all of the depreciation that you took on the house the entire time it was used for business.  So enter the total accumulated depreciation here.

@Kolds57 

Thank you. What about the recalculation using straight line method? There is box that asked for a number. Is this the remaining years depreciation, per year amount? 

The number it asks for is the amount of depreciation you have already or should have claimed on the house. It doesn't care about the remaining years of depreciation.