An angry citizen with a grudge against City Hall and the local newspaper was found dead Saturday morning in his home-made armored tank after a destructive rampage that turned parts of downtown Granby into rubble heaps Friday -- but injured no one except the perpetrator.

Police said they worked much of the night with torches and plastic explosives to break through the foot-thick armor welded to a 53-ton Caterpillar D9 bulldozer. The man who wrecked much of Granby, welder Marvin John Heemeyer, 52, was found dead inside, apparently a suicide.

Before he died, though, Heemeyer had fired machine guns and rifles and smashed his armored vehicle into offices, businesses and a house along Agate Avenue, the main street of this mountain town surrounded by ski resorts, national park land and snow-capped 14,000-foot peaks.

Heemeyer's one-man uprising against the local establishment came to an end about 4:30 Friday afternoon when he rumbled through the front wall of Gamble's Department Store -- a business owned by a planning board member who voted against Heemeyer in a heated dispute in 2000. The front of the massive bulldozer then fell through the floor of the store and was left dangling at an angle, witnesses said.

Police warily approached the vehicle but found it welded shut and armored with a covering of concrete and steel. By Saturday morning, when the driver's hatch was finally blown open, Heemeyer was dead.

"It's amazing what one person can do," said Colorado Gov. Bill Owens (R), who traveled by helicopter to inspect the damage in this town of 1,500. Astonished Granbyites echoed that notion as they strolled main street to assess the ruins.

"City Hall is a pile of bricks, and I mean, that's all," said motel owner Jerry Brenner. "The cement batch plant, up there where he started, that whole factory is going to have to come down. He found his targets, and he wrecked them good."

In a town where everybody knows just about everybody else, many people said they were aware that Heemeyer had been nursing a grudge for years against various residents.

His rage evidently dated to 2000, when he fought in vain to get the local planning authority to block construction of a plant. The factory was approved and went up just across the road from a muffler shop that Heemeyer then owned. He had a running feud with the editor of Granby Sky-High News, the local newspaper, over that planning dispute and other issues.

Neighbors said Heemeyer was forced to sell the muffler shop to pay debts. Recently, a fire at his home destroyed his most cherished possession, his snowmobile -- a vehicle considered essential in a community where winter runs from September to April and brings an average of 100 inches of snow per year.

Working for months in a closed garage, Heemeyer equipped an old bulldozer with three television cameras and monitors so he could see to steer. He cut portholes for his guns, then welded a tight enclosure around them so police bullets could not penetrate. For armor, he poured 12 inches of concrete between metal plates welded to the vehicle. Police found two semiautomatic machine guns, a .223-caliber rifle and two handguns in the vehicle. All those weapons are legal in Colorado.

Heemeyer started down his road to revenge Friday afternoon. He bashed in the cement plant, then rumbled through town to the combination City Hall and library. Librarian Cathy Pritchard said she said she hustled a group of children attending story hour out the back door just before the building fell.

The tank then rumbled back onto the main street and plowed into the newspaper office, which was leveled. Heemeyer smashed a bank, an electric utility office and the house. With the driver's cabin of his vehicle enclosed in armor, Heemeyer clearly had difficulty steering.

"He was veering everywhere, taking out trees and light posts," said Agate Avenue gun shop owner Terri Hertel. "But he only hit the buildings he seemed to be aiming for."

Heemeyer fired several times at the propane tanks at Independent Gas. There was no explosion. He then smashed the home of a former mayor who had supported the cement plant in the planning case, and headed toward his smash-in at the department store. In all, the bulldozer traveled about four miles up and down the main street about 2 mph.

An armored bulldozer driven by Marvin Heemeyer, reportedly upset over a planning dispute, crashes into a house in Granby, Colo., on Friday .