As a firefighter, I think of having a fire in a room, or the cockloft under those A/C units. With the damage to the structure, and the building not being designed for the load, having one of those come down on us is a real possibility.
As an EC, do you have any closer pics for us Joe? And which articles are you thinking of in particular?
The one which first pops to mind for me is about having a 15 or 20A GFCI protected "Heating, Air-Conditioning, and Refrigeration Equipment Outlet" on the rooftop, per 210-63 ('96 NEC).
Edited to add - just looked at my NEC - sorry!
[This message has been edited by DougW (edited 05-30-2004).]