You, or your children, will have to pay off this mortgage. The bank tells you that they gave it to the city to repair infrastructure, build a casino, or carry on a war with your sister city. They try to convince you that it was spent for your own good, or the good of the community. This is precisely the way your federal government treats the excess tax money you contribute to Social Security, Medicare, and other entitlements. You pay special taxes for Social Security, Medicare, airports, and gasoline to provide for both present and future needs.
Excess revenue is supposed to be placed in a trust fund to meet commitments for future periods.
It's used to finance wars, world banking, and pork barrel schemes they could not otherwise afford. This is double taxation plain and simple. It's exactly the same as stealing money from a child's piggy bank, then leaving a note behind. A note that says the child must replace the money you stole. Only the government could do this.