When four antiwar protesters planted a bomb at Sterling Hall in 1970, they shocked the nation and rocked the University of Wisconsin campus. Their deadly work also reverberated across Sauk County.

One of the suspects remains at large, and some of the tracks he failed to cover ran through Baraboo.

The bombers targeted Sterling Hall in Madison to protest the university’s research connection to the U.S. Army. The attack hardly scratched its intended target, the Army Mathematics Research Center, but it killed a physics researcher, wounded others and caused millions in damage to nearby buildings. The incident initiated an international manhunt, one that wouldn’t have been necessary if not for a shift change at the Sauk County Sheriff’s Office.

Deputy Dan Hiller stopped a Corvair matching a description circulated in an all-points bulletin in the pre-dawn hours of Aug. 24. The sedan had pulled off U.S. Highway 12 and onto South Shore Road into Devil’s Lake. Hiller stopped and questioned the car’s four bearded, long-haired occupants as Sgt. Robert Frank and his shotgun provided backup.

Suspicions abounded. The four – Karl Armstrong, his brother Dwight Armstrong, Leo Burt and David Fine – said they had come to Devil’s Lake to camp, but had brought no gear. They didn’t have a key for the trunk. And they offered conflicting reports on their whereabouts the previous night.

“I had a really curly hair go up on the back of my neck. I knew these guys were the guys,” Hiller said.

But a warrant had yet to be issued, and a check of the suspects’ records revealed no cause to hold them. Madison police, deluged with calls related to the bombing, were too busy to send a squad.

With the third shift about to give way to the first, Frank headed back to headquarters. Hiller was due to follow him, but asked to stay and monitor the suspects. Sheriff Ralph Hearn told Hiller he didn’t want to pay overtime, and would instead send a squad to relieve him. Hiller was to return to the station.

“As soon as I drove out, I’m sure they took right off,” Hiller said. “I didn’t want to leave.”

That turned out to be law enforcement’s best – and last – chance to catch all four bombers. They fled to Canada and disappeared, making the FBI’s “most wanted” list. Three of them – Fine and both Armstrongs – eventually were arrested, tried, imprisoned and freed. Last seen at a Canadian boarding house, Burt was never caught.

The Sterling Hall bombing was a turning point in the anti-war movement. Intended to show the government that the American people would use any means to stop the escalation of war in Vietnam, the bombing instead cured protesters of their thirst for blood and turned public sentiment against hippie radicals.

“It was a terrible time in this country,” said Hiller, who served on a riot squad that frequently patrolled State Street and the Capitol in Madison. “They were going to stage an all-out, almost like a revolution, I would call it.”

Local connections to the national tragedy – the bombing represented America’s most heinous act of domestic terrorism until the 1995 attack on the Oklahoma City federal building – were noted in almost daily updates in the Baraboo News Republic. Hiller was interviewed on Madison television and, in later years, by book authors. People still ask Hiller about the incident today.

“When you have something that large and that huge, people don’t forget it,” he said.

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Local connections

At the time, the Devil’s Lake traffic stop was the first known local tie to the bombers, but it turned out to be the last of several. The conspirators’ campaign of domestic terror, concluding with the Sterling Hall bombing, had ramped up for nearly a year in Sauk County. A failed attempt to bomb the Badger Army Ammunition Plant on Dec. 31, 1969, earned the group the nickname the New Year’s Gang. The gang later tried, again unsuccessfully, to attack a Prairie du Sac electric substation that powered the plant.

In the days leading up to the Sterling Hall attack, the bombers bought ammonium nitrate, a key ingredient in their incendiary mix, from a Baraboo fertilizer plant. They mixed it with fuel oil at a remote staging area in the hills of Greenfield Township.

Roger Stieve of Baraboo was managing the fertilizer plant at the Farmers Union Co-op on Lynn Street when Karl Armstrong, a UW dropout claiming to be working for a local farmer, asked to buy ammonium nitrate in bulk. It wasn’t an unusual request.

“I didn’t question it. I was there to sell stuff, so that’s what I did,” Stieve said.

A few nights later, he learned of the explosion while watching news on television. He told his wife, “I think I know what they used, and I think I know who sold it to them.”

The fertilizer-and-fuel mix demonstrated that the bombers had grown more sophisticated. The late Tom Bates wrote in his 1992 book “Rads” that Karl Armstrong previously had bombed Madison buildings with military ties – the campus ROTC building and a primate lab he thought was a Selective Service office – using Molotov cocktails.

In his hastily planned attempted bombing of the Badger plant, Armstrong chose a different weapon – a mixture of ammonium nitrate and kerosene. He filled mayonnaise jars and an ashtray with this mixture and convinced his brother Dwight, a novice pilot, to help him steal a plane and drop the bombs on Badger.

They stole a plane and flew through snow flurries over the active munitions plant. Narrowly missing power lines on their descent to 750 feet above the plant, they dropped the jars and ashtray on Badger before landing at Sauk Prairie Airport. There Karl Armstrong’s girlfriend, Wisconsin Dells native Lynn Schultz, was waiting with a getaway car and flares to guide their landing.

None of the bombs detonated. The stolen Cessna 150 was found sitting in the middle of the runway the next day at the airport. Although unsuccessful, the caper was considered the first air bombing of a U.S. military installation since Pearl Harbor.


In the years after the bombing, America de-escalated its involvement in Vietnam, and peace returned to UW. Karl Armstrong was caught in Toronto in 1972, as was his brother five years later. Fine was caught in 1976.

Those three served their time, and Karl and Dwight Armstrong later opened Radical Rye Deli in Madison. Dwight died in 2010 of lung cancer. That year, new leads surfaced regarding Burt’s whereabouts after he was featured in an episode of “America’s Most Wanted.”

Hunted by generations of agents, Burt is the longest-running FBI fugitive. Leads have led his pursuers to several countries and U.S. states. Until Ted Kaczynski was caught, Burt was suspected as the Unabomer. As recently as May, the Philadelphia Inquirer reported, Burt sightings have been called into the FBI’s Madison office. He would be 66 today.

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