Never antagonize someone who has a short fuse, a long memory, and a big bulldozer.

A wise old sage (Arnold Schwarzenegger, perhaps?) once said, “Don’t get mad; get even.” Disgruntled businessman Marvin Heemeyer did both. First, he got extremely mad at the residents of the Colorado resort town of Granby for slights both real and (mostly) imagined. Then he got even. Perhaps a little more than even. After months of single-minded work and planning, on June 4, 2004, he unleashed a revenge so diabolical, so destructive, and so bizarre that it was worthy of a James Bond villain.

They’ll certainly never forget about it in Granby—the parts that are still standing, that is.

Like most stories of crazed retribution, this reckoning was a long time coming. Heemeyer moved to Colorado from South Dakota, and by the early nineties he’d built up a chain of successful muffler shops in nearby Boulder. The money was good enough to allow him to move to the resort community of Grand Lake, about sixteen miles from Granby. In 1992, he opened a Granby operation called Mountain View Muffler.

Marvin Heemeyer’s bullet-proof, 61-ton bulldozer.

When he wasn’t riding a snowmobile, hiking, or otherwise enjoying the great outdoors, Heemeyer dabbled in various civic causes. Trouble was, he often didn’t get his way—and he was a sore loser. In 1994, he championed a failed attempt to bring gambling to Grand Lake. He didn’t take kindly to the proposal’s defeat, and during the struggle he almost came to blows with the town’s newspaper editor, who opposed the measure.

Things got even uglier in 2000, when the town of Granby started a debate over whether to locate a concrete plant next to Heemeyer’s muffler shop. He said he was angered by the noise and dust the project might create. But he also had a problem with the project’s operator, Cody Docheff, to whom he’d made an abortive attempt to sell his property. The Granby town board tried to referee the sparring match between the two, but it was obvious to those involved that it was metastasizing into something far more personal and venomous than just a hassle over a bit of territory.

In 2001, the town board finally decided in favor of the plant. Heemeyer filed a lawsuit challenging the decision, which also failed. Then, in 2003, he got into another dustup with the city over whether his muffler shop had to be hooked up to the city sewer system. It seemed like small potatoes, and to a person with adequate anger-management skills, it would have been small potatoes. But in Heemeyer’s mind it became a very, very big problem.

Unknown to anyone at the time, he started plotting his revenge—the instrument of which would be a sixty-one-ton (55 metric ton) bulldozer he’d purchased several years earlier and stored in a building next to Mountain View Muffler. In December 2003, he sold both the shop and the building housing the dozer, with the proviso that he keep the use of the two-thousand-square-foot (185 sq m), walled-off section where the massive machine sat. In March of that same year, he also deeded his house to a friend, then moved into the work space to do some serious customizing.

It was quite a job for one man—even a man fueled by a highly unstable mix of rage and lust for vengeance. Heemeyer, an expert welder, slowly turned his civilian bulldozer into an armored war machine. First he shielded the cab by sheathing it in two layers of heavy steel with concrete poured between them. He could keep tabs on the outside world by looking at three TV monitors linked to exterior cameras encased in shatterproof, high-impact plastic. Three high-powered rifles were mounted inside this fortified redoubt, pointing fore, aft, and to one side.

The neighbors got their first look at Heemeyer’s pimped-out ride on the fateful afternoon of June 4. According to some reports, before he climbed into the bulldozer’s armored cab and bolted the hatch shut behind him, he greased the exterior to prevent attackers from scrambling up its sides. Of course there wasn’t a door in the building big enough for the dozer to drive through, but that wasn’t a problem. Heemeyer simply fired up the 410-horsepower (305 kw) engine, pointed the dozer at the nearest wall, and made one.

Heemeyer’s death dozer tossed a pickup truck through the offices of a construction firm.

The first target, not surprisingly, was the cement plant next door. Heemeyer’s machine pulverized the company’s administrative building with the ease of a smoker grinding out a cigarette butt. Then he took off the back half of the factory proper. All this in spite of the fact that Docheff, Heemeyer’s nemesis, quickly climbed aboard his own piece of heavy construction equipment and tried in vain to stop the destruction by ramming the armored bulldozer.

Once he was satisfied with the level of carnage, Heemeyer went calling on folks in town. Rumbling down Granby’s main drag with an ever-growing line of police vehicles in pursuit, he took the front off the headquarters of the local electric company, tossed a pickup truck into the offices of a construction firm, annihilated the town hall, and smashed the office and printing plant of the local newspaper, the Sky-Hi News. Police peppered the massive rig with bullets, but their small arms were useless against the moving metal mountain. “I watched a police officer fire many rounds at it, and he may as well have been using a squirt gun,” one bystander told CBS News.

Then Heemeyer, who had written a list of targets that he carried along with him on his rampage, ran over the home of the town’s deceased ex-mayor. Next it was on to the Independent Gas Company, where he spent a few minutes trying to ignite the company’s propane storage tanks by firing at them with a .50-caliber rifle. Failing at that, he then trundled up to a hardware store (owned by a town board member) and leveled it. During the process, the engine finally gave out on his dozer. Police quickly swarmed the vehicle, and moments later a single gunshot from inside was heard. Heemeyer had killed himself with a pistol. In a final, macabre salute to his workmanship, it took hours to extract his body from the cab.

In retrospect, his choice of vengeance was as unique as it was inexplicable. One of the biggest mysteries isn’t how he managed to keep such an elaborate plan secret, but why he bothered with something so ridiculously excessive in the first place. The bottom line is that a zoning dispute and some sewer work cost him his life. Perhaps, considering the outcome, the better approach would have been to shrug the whole thing off.

He may have left an indelible imprint on the memories of Granby’s inhabitants, but not on their real estate. Insurance money quickly replaced what was damaged. Even the concrete plant, the focus of so much ire, was back in operation almost immediately. Still, there was one lasting civic improvement: Sour grapes Heemeyer and his killer bulldozer were no more.