Marvin Heemeyer was a skilled welder in Granby, Colorado, who felt wronged by the local government. After a zoning dispute destroyed his muffler shop business and fines piled up, he decided he had nothing left to lose. He didn't hire a lawyer; he bought a Komatsu bulldozer. "The Concrete Tank" tells the story of the "Killdozer."

For 18 months, Heemeyer secretly modified the bulldozer in his shed, encasing it in layers of steel and concrete that made it impervious to small arms fire and even explosives. He installed cameras for visibility and air conditioning for comfort. On June 4, 2004, he sealed himself inside—with no plan to ever come out—and went on a rampage.

This book avoids glorifying the violence but analyzes the "snap." It details the two hours of destruction where he systematically flattened the town hall, the mayor's house, and the businesses of his enemies, while police fired futilely at the armor. It is a tragedy about the tipping point of rage and the terrifying capability of a man with a grievance and a welding torch.