A smash-and-grab burglary at a Nevada City jewelry store didn't prove profitable after an employee at a neighboring business witnessed the break-in and called 911.The night-shift employee in the 200 block of Broad Street heard glass breaking just before 3 a.m. Tuesday and looked out the front window, said Nevada City Police Lt. Lorin Gage.The person, who was working at the National Hotel, was able to see a white SUV-type vehicle and a sedan; the SUV apparently had used a chain to yank the metal grate "security" door off La Cache.According to jewelry store owner Jim Rudisill, a passing taxi …