Sterling Hall bombing

In the early morning of August 24, 1970, a bomb built from nearly 2,000 pounds of ammonium nitrate and fuel oil (ANFO) exploded outside Sterling Hall on the University of Wisconsin–Madison campus. The device, loaded into a stolen Ford Econoline van, was detonated at 3:42 a.m. and was intended to destroy the Army Mathematics Research Center (AMRC), a U.S. Army-funded think tank occupying the second through fourth floors of the building's southern wing. The explosion caused massive destruction across Sterling Hall and damaged 26 nearby buildings, with pieces of the van found atop an eight-story building three blocks away. Ironically, the AMRC itself was only lightly damaged. Total damage to university property exceeded $2.1 million (about $16.2 million in 2025 dollars).

The blast killed Robert Fassnacht, a 33-year-old postdoctoral physics researcher who had gone to his basement laboratory that night to finish superconductivity research before a family vacation. He was found by rescuers face down in about a foot of water. Neither Fassnacht nor the physics department was affiliated with the AMRC. Three other people were injured: graduate student David Schuster, who suffered a broken shoulder, fractured ribs, a ruptured eardrum, and lasting hearing loss after being trapped in rubble for three hours; postdoctoral researcher Paul Quin; and university security officer Norbert Sutler, both of whom suffered cuts and bruises from shattered glass.

The bombing was carried out by four men — Karleton "Karl" Armstrong, his younger brother Dwight Armstrong, David Fine, and Leo Burt — who called themselves the "New Year's Gang," referencing an earlier failed attempt to bomb the Badger Army Ammunition Plant from a stolen airplane on New Year's Eve 1969. The group targeted the AMRC as part of broader opposition to the university's research ties to the U.S. military during the Vietnam War; the center had become a focal point for anti-war protests after student newspaper The Daily Cardinal published investigative reporting linking AMRC's work to Department of Defense counterinsurgency requests.

Karl Armstrong was captured in Toronto in February 1972 and sentenced to 23 years, serving seven. Dwight Armstrong was arrested in Toronto in April 1977, pleaded guilty, and was sentenced to seven years, serving three; he later returned to Madison and died of lung cancer in June 2010. David Fine was captured in San Rafael, California, in January 1976 and sentenced to seven years in federal prison, serving three; he was later denied admission to the Oregon bar despite passing the bar exam. Leo Burt fled to Canada with Fine after the bombing and, as of May 2023, has never been located or apprehended; he has not been convicted and remains at large. The Army Mathematics Research Center itself was phased out by the Department of Defense at the end of the 1970 fiscal year.