'Is it a killer cloud?’ 1992 benzene leak blanketed and terrorized portions of Minnesota and Wisconsin

The chemical cocktail created an orange colored vapor cloud measuring 20 miles long and 5 miles wide — and it parked itself over the populated area of Superior, Wisconsin, and neighboring Duluth, Minnesota, prompting a mass evacuation of more than 50,000 people.

Aerial of the train derailment and toxic benzene spill in the Nemadji River in 1992. (file photo / News Tribune)

In the early morning hours of June 30, 1992, Duluth’s newly minted police chief, Scott Lyons, answered a phone call that would turn an otherwise pleasant summer day into a nightmare.

In the minutes before 3 a.m., as Minnesota's Northland slept, a freight train carrying hazardous materials just south of Superior, Wisconsin, had derailed, sending train cars carrying chemicals sailing 71 feet into the waters of the Nemadji River.

The result was catastrophic — the chemical cocktail created an orange-colored vapor cloud measuring 20 miles long and 5 miles wide — and it parked itself over the populated area of Superior and neighboring Duluth, prompting a mass evacuation.

“We had know idea what was in that cloud,” Lyons said in a recent interview with Forum News Service. ”And so that was our biggest concern: You know, what is it? Is it a killer cloud? Is it nothing?”

While Lyons and his crew were scrambling to figure out what chemicals the rail cars were carrying — and, therefore, what chemicals were swirling around in the sky — police officers attempting to alert residents began coming down with troubling symptoms.


Some reported burning eyes, skin and throats. They weren’t the only ones. Seventeen people were treated that day at area hospitals, according to the Associated Press.

Pictured is an Associated Press article in the California paper, The Press Democrat, about the 1992 benzene oil spill south of Superior and Duluth, which led to the evacuation of more than 50,000 residents.
Pictured is an Associated Press article in the California paper, The Press Democrat, about the 1992 benzene oil spill south of Superior and Duluth, which led to the evacuation of more than 50,000 residents.<br/>
Photo provided by

Meanwhile, near the site of the river, hundreds of dead fish were rising to the surface.

As news of illnesses rolled in, and with no answers concerning the potential dangers the unknown chemicals posed on area residents, city officials in both Superior and Duluth ordered a mass evacuation.

“It was chaos. It just was chaos, because we didn’t know,” Lyons said.

Nobody was allowed to enter the evacuated areas, creating an eerie ghost town underneath the low-hanging toxic cloud.

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In the minutes before 3 a.m. on June 30, 1992, as the Northland slept, a freight train carrying hazardous materials just south of Superior derailed, sending train cars carrying aromatic chemicals sailing 71 feet into the waters of the Nemadji River. 

The result was catastrophic —  the chemical cocktail created an orange colored vapor cloud measuring 20 miles long and 5 miles wide — and it parked itself over the populated area of Superior and neighboring Duluth. As a result, more than 50,000 residents were evacuated. 

Reporter Trisha Taurinskas recalls the scary situation and speaks with then-Police Chief Scott Lyons about the events of that day. 

A killer cloud?

When law enforcement became aware of the train derailment, the answers regarding the contents of the train cars weren’t immediately clear. They knew there were hazardous chemicals on board, but the specifics weren’t readily available.

“We opened up our emergency operations center just because we didn’t like what was going on,” Lyons said. “It was just one of those things, we didn’t know what was in the rail cars. We didn’t know if they were leaking — as it turns out, that was true. So, there we were. Having to then deal with that situation, especially as the sun came up and the cloud was there.”


For a brief time that morning, Lyons and his crew thought that Mother Nature was on their side. The wind had temporarily blown the cloud north over Lake Superior, essentially sweeping the problem away. Yet, the wind switched, inviting the chemical cloud back to the Duluth and Superior areas, where it would hover for hours.

With the train’s staff unable to answer questions, Lyons and his team went to the source: the manufacturing company that was transporting the product.

Lyons told the Duluth News Tribune in 2012 that his chief deputy, Bob Larson, made the call. While the company was at first reluctant to give answers as to the nature of the chemicals and the risk it posed to the tens of thousands exposed, Larson eventually got an answer out of him — and it wasn’t good.

The company’s chief medical officer said that if his family was living in the area, he’d get them out — immediately.

And so began the evacuation.

More than 50,000 residents were evacuated from their homes — by some estimates, the number was closer to 80,000. School activities and daycares released children to their families. Residents living above the hill in Duluth were told to shut their windows and stay inside.

Area hospitals were evacuated, jail inmates were transported to areas outside of Duluth. Nursing home residents were also ushered out.
“You think it’s not that big of a deal, but then you have to realize the type of people you have to move,” Lyons said. “You’ve got St. Ann’s Home and you’ve got Lakeshore Home. And, all of a sudden, they can’t be in those homes because that cloud is coming right at them.”

Pictured is a woman packing her car before evacuating the Duluth area in 1992 after a train derailment created a toxic 20-mile benzene cloud that blanketed the area.
Melissa Gergin of Duluth, Minn. was one of 50,000 area residents who were forced to evacuate their homes in 1992 following a train derailment south of the Duluth-Superior area. The train, which was carrying benzene, fell into the Nemadji River, creating a 20-mile long vapor cloud that hung over the Twin Ports.
File / Duluth News Tribune


Working together

While Lyons is quick to point out the day was a swirl of worry and chaos, he also points to that day as one of the most inspiring and rewarding of his career.

Simply put, people worked together swiftly to get people to safety. While criticism came later, Lyons said he witnessed community organizations, businesses and residents come together to save one another from a perceived dangerous threat.

From 30 years in the future, that type of cooperation — without immediate disagreement — can be rare. Differing opinions on the severity of the situation and how it could be handled are often at play. Yet on that summer day, people got to work to do what they felt was right in the circumstances.

“I still look at that as one of the neatest things to have been a part of because so many people jumped in,” Lyons said.

Family evacuates
Ben and Chris VanLierop had precious cargo when they shot up to Central High School on June 30, 1992 -- 10-week old Johan. "It was scary," Chris said Friday from her home in Hopkins, a Minneapolis suburb, when recollecting a long day spent in the school gym as parts of Duluth were evacuated after a benzene spill.
File / Duluth News Tribune

While the vast majority of residents in the evacuation zones quickly made their way out of the city, there were some who stayed behind to take advantage of the silence. Lyons said that was one aspect of the benzene spill day that is often forgotten about.

“Some people who didn’t want to leave weren’t, in our estimation, weren’t people who just weren’t going to leave,” Lyons said. “They were thinking, well, this looks like an opportunity.”

Despite the perceived threat and the mass evacuation at play, law enforcement officers did still have to provide policing in the danger zones.

That afternoon, as the cloud dissipated, residents drove back into the evacuated areas. Those living on the outskirts of the evacuation zone came up from their hiding places and opened their windows.


While the hospital did see patients who were impacted by the toxic cloud, the day of chaos had come to a close with no fatalities.

The long-lasting effects, however, wouldn’t be fully known until years later.

What happened to the train cars?

Following the incident, it was determined that a faulty rail line was responsible for the benzene oil spill.

A 2012 article in the Duluth News Tribune states that the rail line had been inspected one month before the accident — a procedure that was conducted by Burlington Northern inspectors. The company’s inspectors did find a crack in the rails, but claimed that it was safe by Federal Railroad Administration rules. An ultrasound conducted by Burlington Northern experts revealed nothing.

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However, as the train rolled down the tracks in the early hours of June 30, 1992, those working on the rail cars felt the train derail. The National Transportation Safety Board evaluated the rail line following the incident and determined that the damage occurred inside the steel. The cracks on the surface, observed by inspectors, had interfered with the ultrasound images.

The rest, as they say, is history.

The lawsuit

In the months following the Benzene oil spill, Superior Attorney Toby Marcovich filed a class-action lawsuit on behalf of those impacted by the oil spill in the Douglas County area. The railroad company settled at that time for $2.5 million.

At the end of the claim period, $500,000 remained on the table.


Dale Bartz was a railroad bridge inspector who responded to spill site days after the train went into the river. Bartz notes that he wasn’t provided with protective equipment. By 2006, he was diagnosed with stage 3 multiple myeloma, a condition his doctor at the time claimed could have been caused by exposure to the chemicals at the spill site.

In 2013, Bartz had requested $750,000 from the class-action lawsuit unclaimed funds. Ultimately, a judge denied Bartz’s claim.

The $500,000 had grown, through investments, to $1.3 million and was ultimately split among the Duluth Superior Area Community Foundation, University of Wisconsin-Superior and Wisconsin Indianhead Technical College, located in Superior.

Benzene spill
Aerial view of the derailment that caused the 1992 benzene spill. At bottom is the Nemadji River with a tanker car in it. (1992 file / News Tribune)

While Bartz wasn’t able to collect, his lawsuit did bring up an important question: What kind of damage did exposure to the spill site yield long term? And, were there long-term consequences for those in the Duluth-Superior area who were exposed to the chemical cloud?

To this day, it’s difficult to say.

Prolonged exposure to benzene is considered a cause of cancer in humans, according to the Department of Health and Human Services . The question, though, is whether short-term exposure to high amounts of benzene yields the same consequences.

Whatever the answer, Lyons said he believes city officials in Superior and Duluth did the right thing that day. Without sufficient information regarding the contents of the train car and chemical cloud, they had to assume the worst, and keep their residents from succumbing to the mysterious — and potentially dangerous — orange cloud.

Trisha Taurinskas is an enterprise crime reporter for Forum Communications Co., specializing in stories related to missing persons, unsolved crime and general intrigue. Her work is primarily featured on The Vault.

Trisha is also the host of The Vault podcast.

Trisha began her journalism career at Wisconsin Public Radio. She transitioned to print journalism in 2008, and has since covered local and national issues related to crime, politics, education and the environment.

Trisha can be reached at
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