They are unpeopled scenes: New Orleans as our modern Pompeii. Mr. Polidori stood near the corner of Law and Egania Streets where a plain, single-story cottage with a hole in the roof rests beside a telephone pole. A crisscross of power lines forms a shallow X against the empty blue sky. The house, pale green and white, recedes, diagonally.

Except that — the image can take a second to decipher — there are two cottages, one green, one white. During Katrina, the green one, like Dorothy’s house, floated clear across Egania Street from who knows where, stopped perpendicular to its neighbor by those electric lines, which acted like arrestor wires on an aircraft carrier, ripping open the hole in the roof.

If this sounds confusing, that’s the nature of chaos, which can be as hard to photograph as it is to describe. Fortunately, Mr. Polidori is a connoisseur of chaos, and the beauty of his pictures — they have a languid, almost underwater beauty — entails locating order in bedlam.