fargobob said "It can be very close quarters through that section of Princess ave. with all the snow at roadside. It's possible the mirror got clipped by another vehicle or a poorly loaded truck or trailer. Also, the picture does show a tire track pretty close to the vehicles parked along the side of the road. "
I was driving by as he was taking the picture. The bus ahead of me was very close to the car. Pretty sure it was clipped by another mirror, Good luck finding out who. Wonder if WMCA has cameras.