When I first saw the signs along the sidewalk reading “Caution: Falling Ice” I had a vaguely disquieting sensation. At first I attributed it to concern for my noggin. Then I thought it was from surprise that buildings keep a sign like this in storage, ready to deploy every winter. Then I realised the true purpose of those signs.
Many modern buildings of the glass-and-steel-box genre take their cue from the designs of Mies van der Rohe, and have thin vertical I-beams grafted onto their exterior skins. Though they look structural, these beams are purely decorative, providing vertical continuity and mild shadow-play to otherwise drab cubes. The trouble is, in the winter wind the beams act as excellent ice collectors… and since they’re vertical, they shed readily.
So the fact of the matter is this: the owners put those “Caution: Falling Ice” signs out not for your protection, but for theirs, to preempt a lawsuit when one of these inherently dangerous buildings decides to drop a load of ice on your head… thanks to a cosmetic detail.