Heemeyer dozer a CAT D9 or a Komatsu D335A Civilian incident illustrating the D9 s power Please note Local newspapers are quite specific in identifying the Heemeyer bulldozer as a Komatsu D335A not a Caterpillar D9 On the 4th of June 2004 a Granby Colorado USA resident by the name of Marvin Heemeyer ran amok driving a modified D9 and destroyed several houses and community buildings in the small farming village of Granby He crashed the buildings of his adversaries in a zoning dispute involving his muffler shop and a new concrete mixing plant Heemeyer fitted makeshift concrete armor to the vehicle turning it into a tank like mobile fortress The cabin engine and tracks were protected by reinforced concrete armor that was in places over one foot thick The driver s vision of where he was going was provided by video cameras outside the driver s compartment feeding three CRTs inside Heemeyer also provided food water and air conditioning for himself inside the fortified driver s cabin The bulldozer was armed with several rifles and a 50 caliber 12 7 mm gun The D9 itself was an old model that was no longer in production During the one and a half hour rampage law enforcement officers fired hundreds of bullets at the makeshift tank and set off explosive charges against it but could not stop the D9 s rampage Finally the fortified D9 came to rest trapped in the rubble of a collapsed building A failed radiator brought the vehicle to a halt Heemeyer apparently took his own life in his cockpit while SWAT teams were using explosives and oxy acetylene cutting torches to gain access to the driver s compartment Although nobody else was killed in the incident property damage was very extensive According to many reports Heemeyer went out of his way to avoid killing innocents and apparently the purpose of his rampage was solely to cause extensive property damage to his enemies See killdozer bulldozer