From The Consumerist:
It’s demolition derby time at this Walmart parking lot where a tractor without anyone behind the wheel drives around in a circle of death, plowing through minivans and raising sparks as its blade gouges the side of the building.
About 3 minutes in is where it starts really crashing into the cars. Despite someone finally coming to try to jump into the cab, they’re not able to until the tractor crashes head-on into a light pole and stops.
John Deere tractors come equipped with a seat kill switch that shuts off the engine if there isn’t someone sitting there. Either this one wasn’t working or someone had disengaged it – a big safety no-no.