Explosion, fire in Marengo fuel plant leads to injuries and evacuation

Editor's note: This story has been updated to indicate that C6-Zero is an alternative fuel plant that does not handle biofuels.

An explosion resulted in a fire and multiple injuries at an alternative fuel plant in Marengo Thursday morning, prompting the city to urge residents to evacuate and avoid the area.

Firefighters battled the blaze until 4:30 a.m. Friday, when it was fully extinguished and fire operations were completed, Marengo police chief Ben Gray said. Multiple injured people remained at University of Iowa Hospital and at least one in serious condition at the burn unit, Gray said Friday morning.

The fire, at the C6-Zero plant in the 800 block of East South Street, caused city officials to urge all residents to avoid being outside because of the dense smoke. The Iowa County Sheriff's office also urged residents to avoid the area.

The latest from Marengo authorities

The city of Marengo late Thursday said in a news release that all people in the plant at the time of the explosion had been accounted for. It said five people were taken to the University of Iowa Hospitals & Clinics by ambulance and that an unknown number went there or to a local hospital, Compass Memorial, via personal vehicles. Fire crews continued to battle the blaze which started at 11:16 a.m., and the cause remained under investigation, the city said.

What we know about the C6-Zero plant where the Marengo explosion occurred

The Iowa County assessor’s site shows the property is owned by Heartland Crush, a business that has encountered financial difficulties in recent years.

In 2018, a district court appointed the Iowa Department of Agriculture as receiver of the business after the agency received a complaint indicating the company did not have a grain license.

Heartland Crush started getting a grain license in 2017 but never completed the process, the state said in court filings. The state agency said it found about $1.1 million of unpaid grain. The company negotiated payments to all grain sellers, the agency said.

In 2020, Grinnell State Bank sought to foreclose on Heartland Crush, naming Jeff Buresh and four other individuals, saying the business had defaulted on a 2017 loan and owed the lender about $430,000. The company reached an agreement with the bank, whose attorney filed a document in August of this year saying the company owed about $389,000.

What does the plant do?

Initially, as firefighters battled the blaze, there was confusion about what the plant produced. According to Iowa secretary of state records, it is still owned by Heartland Crush, a soybean mill. But the plant is now occupied by a company called C6-Zero. That company says online that it recycles discarded asphalt shingles, using what it describes as "a large washing machine" filled with a proprietary solution to separate the fiberglass, oil and sand they contain. Those products are then sold to be reused and repurposed, the company says.

Officials on the scene called the facility a "biofuel" plant, but the process C6-Zero described does not involve turning a biomass into fuel ― unlike, for example, processing corn into ethanol or soybeans into biodiesel.

The Iowa Department of Natural Resources said Thursday it has been in discussions with C6-Zero officials about the permit the company needs to operate in Iowa. The agency hadn't fully determined yet which environmental regulations may apply to the business, based on what it knew about the manufacturing process so far. On Friday, the agency said it had received no complaints about the facility.

10 to 15 patients treated at University of Iowa hospital

The University of Iowa Hospitals & Clinics is treating 10 to 15 patients, Chief Medical Officer Dr. Theresa Brennan said Thursday afternoon. Most of those patients suffered mild to moderate injuries, ranging from cuts and scrapes to burns and trauma, Brennan said.

Brennan said during severe emergencies, the hospital classifies patients as being in green, yellow or red categories, ranging from least to most severe. Only one patient being treated by the hospital is in the red category, she said.

Brennan said the hospital was well-equipped to handle this type of emergency.

"We were prepared to take many more patients than this. Mobilization during an emergency is what we do best," she said.

At 4 p.m., fire still burned at the plant, 'it can be an all-night thing'

Iowa State Patrol Senior Trooper Bob Conrad said of the fire, “it can be an all-night thing.” He said he was glad to see there was less smoke than earlier but the response was still ongoing.

Patrol trooper: At least 30 were inside the building, no fatalities reported

At least 30 people were inside the plant when it exploded and caught fire, according to Conrad. There were no fatalities reported as of 2:30 p.m.

All of the surrounding counties had sent fire personnel to assist with battling the continuing blaze, Conrad said. He said the cause of fire had not been determined.

Conrad said several people inside the building sustained injuries and had been transported to the University of Iowa and other local hospitals.

Public safety officials were monitoring air quality and groundwater quality, he said. He said public safety officials from multiple jurisdictions in the surrounding areas worked together to contain the threat to the public.

Expert says dust can be source of fire in manufacturing facilities

Officials haven't said what may have caused the explosion at the plant, but high concentrations of dust can be a source of fires in grain handling and manufacturing facilities, said T. Renée Anthony, director of the Great Plains Center of Agricultural Health at the University of Iowa.

When large sources of settled dust become airborne and there's a spark — anything from an overheated bearing to an electrostatic shock — can cause a fire, Anthony said.

Inside an enclosed space, an expanding fire creates pressure that can lead to an explosion, she said.

“A lot of agricultural products do have combustible dust of concern,” said Anthony, who pointed to dust that caused an explosion at a sugar plant in Georgia that killed 14 people in 2008.

Another source of fires and explosions is flammable gas inside an operation, she said.

Plumes of smoke seen 5 miles from town

Over the fields and roads leading into Marengo, dark plumes of smoke billowed over town at 2:30 p.m.

Residents told to go to Williamsburg, next town south of Marengo

All homes east of Eastern Avenue in Marengo were evacuated and residents were told to head to Williamsburg, the next town south, according to fire officials on scene. At 2 p.m., it was unclear if there was a specific shelter available to evacuees.

Williamsburg City Clerk Niki Osweiler told the Des Moines Register shortly after 2 p.m. the city did not have information about the evacuation.

The city of Marengo also warned residents still in town via Facebook that their water may be brown due to extra water usage from the fire.

Drone footage of the fire from We Are Iowa Local 5 News

Multiple people in the University of Iowa hospital

Multiple patients are being treated at the University of Iowa Hospitals & Clinics, according to hospital spokesperson Jennifer Brown.

"University of Iowa Hospitals & Clinics has received multiple patients following today’s explosion in Marengo and anticipate others may be en route. At this time, we are evaluating the severity of injuries and are working to ensure all patients receive the care they require," Brown wrote in an email to the Register.

Brown encouraged families searching for their loved ones to call 319-356-1616 or 1-800-777-8442.

Where is Marengo?

Marengo is located in eastern Iowa a little over 30 miles from Cedar Rapids and Iowa City. It has a population of around 2,400, according to the most recent census data.

Photos from the facility before the fire

The building where the fire broke out had been owned by Heartland Crush LLC, a soybean processing facility, which opened there in 2017. However, Conrad, of the Iowa State Patrol, said it now operates as C6-ZERO, a fuel production plant.

Francesca Block is a breaking news reporter at the Des Moines Register. Reach her at FBlock@registermedia.com or on Twitter at @francescablock3.

This article originally appeared on Des Moines Register: Marengo, Iowa, plant explosion, fire causes injuries