Marvin John Heemeyer (October 28, 1951 – June 4, 2004) was an American automobile muffler repair shop owner who, following a dispute with town officials, demolished numerous buildings with a modified bulldozer in Granby, Colorado, on June 4, 2004.
Heemeyer had feuded with Granby town officials, particularly over fines for violating city health ordinances after he purchased property with no sewage system. Over about eighteen months, Heemeyer had secretly modified a Komatsu D355A bulldozer by adding layers of steel and concrete, intended to serve as armor.[1]
On June 4, 2004, Heemeyer's feud with Granby culminated in a spree in which he used the armored bulldozer to demolish the Granby town hall, the former mayor's house, and several other buildings.[1] Heemeyer's rampage concluded with his suicide, after his bulldozer became trapped in the basement of a hardware store he had been in the process of destroying.
Heemeyer's bulldozer was a modified Komatsu D355A,[7] which he referred to as the "MK Tank" in audio recordings, fitted with makeshift armor plating covering the cabin, engine, and parts of the tracks. In places, this armor was over 1 foot (30 cm) thick, consisting of 5,000 psi (34 MPa) Quikrete concrete mix sandwiched between sheets of tool steel (acquired from an automotive dealer in Denver), to make ad-hoc composite armor. This made the machine impervious to small arms fire and resistant to explosives. Three external explosions and more than 200 rounds of ammunition fired at the bulldozer had no effect on it.[1]
For visibility, the bulldozer was fitted with several video cameras linked to two monitors mounted on the vehicle's dashboard. The cameras were protected on the outside by 3-inch (76 mm) shields of clear bulletproof lexan.[1] Compressed-air nozzles were fitted to blow dust away from the video cameras.[1]
Onboard fans and an air conditioner were used to keep Heemeyer cool while driving. He had made three gun-ports, fitted for a .50 caliber rifle, a .308 caliber semi-automatic rifle, and a .22 caliber rifle, all fitted with a one-half-inch-thick (1.3 cm) steel plate.
Authorities initially speculated that he may have used a homemade crane – found in his garage – to lower the armor hull over the dozer and himself. Heemeyer apparently had no intention of leaving the cabin once he entered it.[1] "Once he tipped that lid shut, he knew he wasn't getting out", Daly said. Investigators searched the garage where they believed that Heemeyer built the vehicle and found cement and armor steel.[1]
"It is interesting to observe that I was never caught", Heemeyer wrote. "This was a part-time project over a 11⁄2 year time period." He was surprised that several men, who had visited the shed late the previous year, had not noticed the modified bulldozer "especially with the 2,000-pound [910 kg] lift fully exposed ... somehow their vision was clouded".[8]
On June 4, 2004, Heemeyer drove his armored bulldozer through the wall of his former business, the concrete plant, the town hall, the office of the local newspaper that editorialized against him, the home of a former mayor (in which the mayor's widow then resided), and a hardware store owned by another man Heemeyer named in a lawsuit, as well as a few others. Heemeyer had leased his business to a trash company and sold the property several months before the rampage.
The attack lasted two hours and seven minutes, damaging thirteen buildings.[7] It knocked out natural gas service to the town hall and the concrete plant, damaged a truck, and destroyed part of a utility service center.[9] Despite the great damage to property, no one besides Heemeyer (by a self-inflicted gunshot wound) was killed in the event.[1] The damage was estimated at $7 million.[10][11] According to Grand County commissioner James Newberry, emergency dispatchers used the reverse 911 emergency system to notify many residents and property owners of the rampage going on in the town.[12]
Defenders of Heemeyer contended that he made a point of not hurting anybody during his bulldozer rampage.[1] Ian Daugherty, a bakery owner, said Heemeyer "went out of his way" not to harm anyone. Others offered different views. The sheriff's department argued the fact that no one was injured was not due to good intent as much as to good luck. Heemeyer had installed two rifles in firing ports on the inside of the bulldozer, and fired fifteen bullets from his rifle at power transformers and propane tanks.[13]
"Had these tanks ruptured and exploded, anyone within one-half mile (800 m) of the explosion could have been endangered", the sheriff's department said. Twelve police officers and residents of a senior citizens complex were within such a range.[5] Heemeyer fired many bullets from his semi-automatic rifle at Cody Docheff when Docheff tried to stop the assault on his concrete plant by using a scraper, which was pushed aside by Heemeyer's bulldozer.[5]
Later, Heemeyer fired on two state patrol officers before they had fired at him.[5] The sheriff's department also noted that eleven of the thirteen buildings Heemeyer bulldozed were occupied until moments before their destruction. At the town library, for example, a children's program was in progress when the incident began.[2][5]
One officer dropped a flash-bang grenade down the bulldozer's exhaust pipe, with no apparent effect. Local and state patrol, including a SWAT team, walked behind and beside the bulldozer, occasionally firing, but the armored bulldozer was impervious to their shots. Attempts to disable the bulldozer's cameras with gunfire failed as the bullets were unable to penetrate the 3-inch (7.6 cm) bulletproof plastic. At one point, undersheriff Glenn Trainor climbed atop the bulldozer and rode it "like a bronc buster, trying to figure out a way to get a bullet inside the dragon".[2] However, he was forced to jump off to avoid being hit with debris.[2]
At this point, local authorities and the Colorado State Patrol feared they were running out of options in terms of firepower, and that Heemeyer would soon turn against civilians in Granby. Governor Bill Owens allegedly considered authorizing the National Guard to use either an Apache attack helicopter equipped with a Hellfire missile or a two-man fire team equipped with a Javelin anti-tank missile to destroy the bulldozer. This was quickly deemed unnecessary when Heemeyer became trapped in the basement of a Gambles hardware store.[14]
As late as 2011, Governor Owens's staff still vehemently denied considering such a course of action. Since then, members of the State Patrol revealed that to the contrary, the governor did consider authorizing an attack but ultimately decided against it due to the potential for collateral damage of a missile strike in the heart of Granby being significantly higher than what Heemeyer could have caused with his bulldozer.[14]
Various problems arose as Heemeyer destroyed the Gambles hardware store. The radiator of the bulldozer had been damaged, and the engine was leaking various fluids. The bulldozer's engine failed, and Heemeyer dropped a tread into the store's basement and could not get out. About a minute later, one of the SWAT team members, who had swarmed around the machine, reported hearing a single gunshot from inside the sealed cab. It was later determined that Heemeyer had shot himself in the head with a .357-caliber handgun.[1][15]
Police first used explosives in an attempt to remove the steel plates, but after the third explosion failed, they cut through them with an oxyacetylene cutting torch. Grand County Emergency Management Director Jim Holahan stated that authorities were able to access and remove Heemeyer's body at 2 a.m. on June 5.[16]