Unmentioned in all the coverage of the fire yesterday in the apartment of Bernie Madoff associate Ezra Merkin at fabled 740 Park Avenue is the likelihood that he has two very angry and water-damaged downstairs neighbors. But who are the folks who will be calling their lawyers, insurance agents, decorators and architects today? Directly beneath Merkin is none other than financier David Koch, perhaps the building’s most controversial resident, along with wife Julia. And beneath the Kochs reside Dana and Andrew Stone, the latter a banker with a fierce reputation. Tops dogs in monied circles, they unfortunately both sleep in 740’s version of the bottom bunk–and we all know what flows downhill. (Water, silly.) At least they can afford repairs, but still: My sympathies.