WHILE DRIVING (IN MOTION) PASSENGER SIDE MIRROR CAME OFF HITTING THE CLOSED PASSENGER SIDE WINDOW... THERE WAS NO KNOWN OR VISIBLE SIGN OF DAMAGE TO THE MIRROR... IN FACT THE MIRROR LINKAGE WAS FOUND ON THE GROUND ALONG WITH THE MIRROR.. THE MIRROR JUST DISCONNECTED AND FLEW OFF.. A PERSON WAS SEATED IN THE PASSENGER SIDE.. THE LOUD UNEXPECTED BANG WHEN THE MIRROR HIT THE WINDOW SHOCKED THE PASSENGER AND CAUSED A NECK SPRAIN TO THE DRIVER. IF THE WINDOW HAD BEEN OPEN THE PASSENGER WOULD HAVE BEEN HIT IN THE FACE.. ALSO OTHERS IN THE VINCINITY OF THE TRUCK COULD HAVE BEEN HIT BY THE FLYING MIRROR.. THIS TOOK PLACE ON A RESIDENTIAL STREET...