Marvin Heemeyer

Marvin John Heemeyer (October 28, 1951 – June 4, 2004) was an American welder and automobile repair shop owner who, in an act of revenge, demolished numerous buildings with a modified bulldozer in Granby, Colorado, in June 2004. Heemeyer's machine was posthumously labeled by some members of the media and later adopted by some of Heemeyer's supporters as the "Killdozer".

Over the 12 years prior to the attack, Heemeyer became embroiled in disputes with Granby town officials, neighbors of his muffler shop, the local press, and other citizens of Granby, including over zoning rules which Heemeyer believed impaired his muffler repair shop's business. Motivated by his frustration, Heemeyer began secretly armoring a Komatsu D355A bulldozer with layers of steel and concrete in 2002 with the intent of using it for destructive purposes.

On June 4, 2004, Heemeyer used the bulldozer in a vehicle-ramming attack to demolish the Granby town hall, the house of a former mayor, and several other buildings. He killed himself after the bulldozer became stuck in the debris of a hardware store he was destroying. No one else was injured or killed.

Background and personal life Marvin Heemeyer was born on October 28, 1951, on a dairy farm in South Dakota. He was also a doomsday prepper.

Heemeyer was strongly in favor of gambling legalization and campaigned for the cause on several occasions. At one point, he began disseminating a newspaper of his own on the issue, as he believed the local newspapers were biased against this cause. In 1994, a measure was proposed that would have legalized gambling in Grand Lake and Heemeyer was so passionate about the cause that he nearly came to blows with a local reporter who was opposed to the proposal.

Opposition to sell to concrete plant In 1997, the Docheff family planned to expand their business to include a concrete batch plant and were buying up the land around their current lot, hoping to lease the remaining 23 parcels to small manufacturers. He also complained to the Environmental Protection Agency; this resulted in the Docheff family having a professional noise analysis done. Forced to continue forwards and unaware of a small basement on the property, Heemeyer was lured into driving into the building as a means to hopefully pass through it, drive through the other side and continue his attack. However, the tread of the machine slipped into the basement due to its immense weight, essentially deactivating the machine. The radiator had also been damaged, and the engine was leaking, before failing. As such, it was noted that even if Heemeyer had been able to free himself, the bulldozer would not have been able to operate much longer. Cody Docheff stated that "if Heemeyer truly didn't want to hurt anybody, he would have plundered the center of town on the weekend, when most businesses would have been empty". Others have called his rampage domestic terrorism.

Residents and victims have continuous frustration that the town's history is overshadowed by the rampage. During the 20th anniversary of the event in June of 2024, the town hall and the Sky-Hi News office locked their doors to the public. Granby Mayor Josh Hardy released a statement emphasizing the impact the event has on the community and a strong desire for the town to be known for more than the tragedy.

In popular culture Leviathan — a 2014 Russian film originally inspired by Heemeyer's story, although the similarities were no longer obvious in the final version of the script Tread — a 2019 documentary film based on the rampage "Killdozer" — a 2024 song by Madeline Johnston (performing as 'Midwife')