Early this week, when welcome warmer weather was loosening ice and snow on rooftops, a Downtown Improvement District Ambassador urgently directed me to the curb side of the sidewalk I was walking on. “Look out! There’s ice falling from the roof of this three-story building!” I was glad he did, because within moments some ice balls the size of overweight baseballs came crashing down where I’d just been walking. (Only the U.S. Bancorp building on Nicollet Mall, as far as I know, had the forethought to warn pedestrians of the ice hazard.) I’ve invariably found the DID Ambassadors to be friendly, polite and helpful. Now I know a skull-saver.

NANCY B. MILLER, Minneapolis