What airport fees are charged to airlines in the case of operations following an unscheduled landing? A plane may need make an unscheduled landing in the case of a diversion due to mechanical difficulties, unexpected weather, a medical emergency or other reasons (this could even be at an airport with which the operator has no prior agreements).

Airport operators agree various fees with the airlines that use them for their scheduled operations: 


runway/landing fees
fees for stairs, buses to the terminal building, or airbridges
passenger charges, should the passengers need to disembark
parking fees
...amongst others


Which of these charges are typically levied in the case of an unscheduled landing caused by unforeseen circumstances?
A while back I was on my way to Frankfurt on Delta for a business meeting when a frail passenger (who quite honestly should have never been allowed to board in the first place) passed away before getting to the midpoint of the trip. The captain turned the aircraft around and landed at Gander International in Canada, where we spent the night before continuing on our way.

Because I've seen this in the news once in a while, I decided to check the airport's web site to see what is their fee structure. Lo and behold, they publish a comprehensive list of fees that covers everything related to an occurrence of this type.

The fee structure even covers "air rage" incidents under the category of "Emergency" and is charged at so-many-dollars per 1000 kg!


  Emergency
  Including medical, mechanical, air rage, etc.
  $12.57 per 1000kg