Like a bug, unfortunately. Well, technically not the tractor, but the trailer on which it was loaded. I don't know the specifics, but ultimately the trailer started to roll towards his house, and he thought he could stop it. He stepped in front of the trailer (which apparently wasn't connected to a tow vehicle). He realized that wasn't going to work, and tried to step out of the way, but lost his footing. It rolled right over top of him.
Since we live in such a remote area, it took nearly an hour for the paramedics to arrive - and by then he was gone. The guy was in his 70s. It happened in front of his wife and grown kids who happened to be there. Really tragic. The family held on to it for about a year, and then sold it to me (I live on the same mountain).