Because you acquired the home by a gift, your basis usually is the basis that your parents had in the home (what they paid for it, plus capital improvements they made over the years). It may be difficult to reconstruct this information, but their initial cost may be available (e.g., published on Zillow).
Casualty losses such as from a storm, in areas declared by the President to warrant federal assistance. An election may be made to deduct the loss in the year before the loss or the year of the loss.