The indexes consist of personal casualty loss, economic property loss and disaster relief loss.

人员损失主要由因灾死亡损失和因灾伤害损失两部分构成；

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If your property is personal-use property or is not completely destroyed, the amount of your casualty loss is the lesser of your adjusted basis (generally, the cost, adjusted for improvements or depreciation) or the decrease in fair market value of your property.

FORBES: Taxes From A To Z (2013): D Is For Disaster Relief