Marvin John Heemeyer demolished multiple buildings with a modified bulldozer in Granby, Colorado on June 4, 2004.
He was in a fight with his town over fines for violating city health ordinances related to dumping sewage from his business into public spaces.
He secretly created a modified Komatsu D355A bulldozer that was reinforced with layers of steel, bulletproof lexan, and 5000-PSI Quikrete concrete. It had three gun-ports, fitted with a .50 caliber rifle, a .308 semi-automatic rifle, and a .22LR rifle.
He demolished the town hall, mayor’s house, and damaged 11 other buildings. The attack lasted for over two hours. He committed suicide before the police could get to him.