As has been said, the airport fire service will respond to any airfield or off airport incident within the specified radius agreed by the airport authority.
What is really worrying is the fact that the airport fire service only have the media, (fire retardant foam) to put out the initial fire on an aircraft, and only have VERY LIMITED resources to tackle major fires in public areas, freight buildings, fuel farms etc. For this they rely on the local authority fire service.
No doubt airport
PR will try and smooth this over, but there's no doubt that without local authority cover, airports are seriously at risk.