Love them or hate them, plastic bags are nearing extinction in San Francisco.

New technology that detects within seconds when a gun is fired and where the shooter is located is revealing some “troubling trends,” according to city officials.

Nearly 100 seniors, many struggling with debilitating ailments such as dementia and Alzheimer’s disease, will be likely trailblazers among the thousands of people expected to move into new, taller buildings allowed around Market Street under pending zoning rules.