As I remember the story, this was an old guy that had been wronged by the town several times on zoning issues. I think the town was screwing him for the sake of some of their own interests. They down zoned some of his property to protect the interest of a council member or something like that.
He had no help and orchestrated this entire fiasco himself. He welded himself inside the armor plating. There was no door or access hatch.
I like how the town tried to stop him with a 627 scraper. The D9 Cat eats them for breakfast every day! That is what it is designed to do, push those things like toys! His dozer was supposedly an early 70s model D9 and the town also tried to stop him with a 90s model D8. Pretty much all they could do is sit and watch him destroy the town until he ended his own life.
The lesson is don't screw with old people that have nothing to lose!