An explosion and fire at a manufacturing plant in northeast Iowa injured three workers this morning. Allamakee County Emergency Management Coordinator Chris Dahlstrom says it happened around 1:20 a.m. at the Norplex Laminates plant in Postville.

“There was a machine inside the building that exploded,” Dahlstrom said. “There are several large machines and the building is specially made so if something falters…it will go up through the roof and it did do that.” One of the employees who was near the machine is said to have critical injuries.

That worker was airlifted to the burn unit at University of Iowa Hospitals and Clinics in Iowa City. The other two workers were treated for minor injuries. The plant’s sprinkler system helped suppress the fire and keep it from spreading.

The State Fire Marshal’s Office is investigating the cause of the explosion, which resulted in significant damages to the plant. Dahlstrom said the initial damage estimate is listed between $4 million and $7 million.