On that day, I went to my son's school to bought books and school supplies for the new term. We got there around 8.00 am. and finished around 9.00 am. then we walked back to the car to travel back home. Typically, in school hour the road in front of the school building is one-way from kindergarten building toward to the Fine Art building. But on that day is school holidays and have a lot of university student's car to park around school area. While I am staring my car and reverse gear to be space away from the car in front of me , I saw 2-3 cars run counter from Fine Art building to my way I was confused that the traffic patterns has been changed or they are drive the wrong way without careful the car that park behind me I backed my car hit the car behind me which makes that car was damaged (Front bumper scratched and drop slightly) and I have to waste time waiting for officials from the insurance company.