Question
I had (10,000) dinars, and after a year (4,000) dinars were lost. Do I have to pay zakat on the lost wealth?
Answer
You do not have to pay zakat on the lost wealth after a full year has passed; you only owe zakat on the remaining amount, which is (6000) dinars only, because the rule is "If part of the nisab is lost, the zakat is dropped in proportion to it."