The intersection of E. 72nd and Madison Ave. was closed down an hour ago. Why? Because of art!
Somebody had poured an epoxy or plastic resin on two of the intersection's manhole covers, creating a smooth, glass-like surface over the usual manhole-cover ridges and edges. Those familiar metal contours were still visible, of course, which lent the works a challenging textural duality.
The covered covers attracted four fire engines and two police cars. After determining that the pieces - traffic sculptures? reverse reliefs? - weren't any more dangerous than most other modern art, everybody left.
The mystery of the manholes will likely never be solved.