Marvin Heemeyer

Marvin John Heemeyer (October 28, 1951 – June 4, 2004) was an American welder and an automobile muffler repair shop owner. He destroyed many buildings with a custom bulldozer in Granby, Colorado on June 4, 2004.
Heemeyer had feuded with Granby officials. This was caused over many fines for violating city health ordinances when he was forced to dump sewage due to zoning disputes with neighbor.
His feud came to a head on June 4, 2004. Over about 18 months Heemeyer had secretly created a Komatsu D355A bulldozer by adding layers of steel and concrete, intended to serve as armor. He used this to demolish the Granby town hall, the former mayor's house, and several other buildings.
Heemeyer's rampage ended with his suicide, after his bulldozer became trapped in the basement of a hardware store he had been in the process of destroying.