Dumped or stolen

I went back to work today in school to see how I would get on hand was sore but never really used it as I am right handed. 

Found this teachers chair on the way home from work almost on the main road and no idea why it's there, it was not there when I went to the school, so what do you think dumped or stolen?????.

As the camera on this phone is awful I changed it to black and white as the chair is grey. 
Why would someone do this????