Shamus Young created a small Rollercoaster Tycoon amusement park made up of a sidewalk and three balloon stands giving away free balloons. He waited for the visitors to come -- a lot of visitors -- and then built half of a rollercoaster. The tracks end at the edge of the sidewalk so the rollercoaster carts literally plow through the visitors.
It's a little disturbing but in the end everybody lives.
Shamus Young created a small 
