Two Points:
1)
Cover for the Terminals and the Control Towers. Some insurance companies are saying that they will only mantain cover for up to three story buildings.
2)
If there is an airfield crash, god forbid, airfield fire crews would have to deal with the incident on there own and therefore the crash cat. would be reduced to zero. It is possible if there was an off airfield crash, within a certain distance of the field, the airfield crews would attend and therefore this could have a sereve impact on the crash cat.