The Norwalk rail accident occurred on May 6, 1853, in Norwalk, Connecticut and was the first major U.S. railroad bridge disaster; 48 were killed when a train travelling at 50 mph plunged into the Norwalk Harbor off of an open draw (swing) bridge. The accident occurred on the New York and New Haven Railroad where it crosses a small inlet of Long Island Sound via a swing bridge. The approach from New York is around a sharp curve, the signal that the bridge is passable by trains was by way of a red ball mounted upon a tall pole.