A season of fear enveloped much of Iowa 50 years ago in 1970 after six homemade bombs exploded between April 27 and June 29 at locations from Iowa City to Omaha, including three in Des Moines. 

The blasts occurred during the height of anti-war activities that shut down college campuses after four protesters were killed by the Ohio National Guard at Kent State University on May 4. 

The first blast occurred in Iowa City on Monday, April 27, when a relatively small homemade bomb exploded in a downtown trash can shortly after midnight, causing damage estimated at $20,000. 

Two weeks later on May 13, a pre-dawn explosion “rocked the Des Moines police station, … causing extensive damage to the building, knocking out communications and power for a short time and wrecking more than a dozen autos parked nearby,” the Des Moines Tribune reported.

The bomb was placed outside the dispatchers’ office on the first floor and broke windows two blocks away. Damage was estimated at $200,000, and while “more than 35 people, including 16 prisoners and a Municipal Judge were inside, … only one person, a janitor was injured slightly,” the newspaper said. 

Police Chief Wendell Nichols tied the explosion to a May 5 theft of 285 sticks of dynamite from a local supplier. 

The stolen dynamite would be mentioned in news stories about four additional blasts, as well as the discovery on June 21 of an unexploded tool box rigged as a bomb and left under a freeway overpass. 

A third Iowa explosion occurred outside Ames City Hall at 9 a.m. on May 22. That bomb was placed in a window well outside the city jail, and it twisted jail bars “like spaghetti.” Nine people were injured, including a prisoner who was hospitalized in critical condition.

Speaking in Ames, Iowa Gov. Robert Ray expressed concern that most of the stolen dynamite was still unaccounted for despite the recovery of three cases (60 sticks) during a raid on a near-north-side Des Moines home two days after the police station bombing. 

The Omaha police station was a target on June 11. Federal agents compared that midnight explosion with actions against police in Des Moines, Ames, New York, Detroit and Council Bluffs. (The Council Bluffs attack on May 23 involved a Molotov cocktail, rather than dynamite, and caused little damage.) 

A fifth dynamite explosion occurred June 13 in downtown Des Moines at 4:14 a.m. at the Greater Des Moines Chamber of Commerce building. Damage was estimated at $100,000. 

Officials said the chamber explosion was smaller with about half as much dynamite as had been used at the police station. The only injuries were from flying glass to residents of the YWCA across the street. 

The largest explosion occurred June 29. The early-morning target was Drake University’s Harvey Ingham Hall of Science.

Damage was estimated at $250,000 and included “10,000 valuable microscope slides, two research greenhouses” and “several cultures of fruit flies, representing thousands of generations,” the Des Moines Register reported.

The Drake explosion was a puzzle because no government research was conducted at the building, nor were there other activities that might incite an anti-war attack.

But after Drake, the bombings stopped.

It was never clear whether the Iowa bombings were connected or coincidental. They did not appear to be connected with the Weathermen, a national anarchist group associated with other bombings of that era.

Nor was anyone ever charged with the Iowa explosions. 

Four people aged 15-21 were arrested during the May 15 raid by Des Moines police. Two were eventually convicted of possessing blasting caps. But a judge said there was no evidence that dynamite found in a residence associated with the four had been stolen.