Investigators from the Cary Fire Protection District, OSHA and Illinois State Fire Marshals were at Fox Valley Systems on Thursday trying to determine what caused two explosions and the subsequent fire on Wednesday.
Three workers were injured during the blasts, officials said.
Two of the injured were transported shortly after the first explosion, which occured at 1:15 p.m. March 6, to Good Shepherd Hospital in Barrington for treatment. Information was not available regarding the location of the third injured worker.
Since that time, two of the injured were transferred to the burn unit at Loyola Hospital and the third was sent to the St. Anthony Hospital Burn Unit in Rockford, according to Cary Fire Lt. Andy Veath.
Veath said the investigation is ongoing into what amounted to a nearly five-hour long fire. The blaze required the evacuation of nearby buildings due to the paint and chemicals contained the building.
Fox Valley Systems is located at 640 Industrial Dr. in Cary. The company manufactures paint and equipment used for striping athletic fields, according to its website. The building sits adjacent to the Metra train tracks and Route 14.
The explosions blew out the front wall of the eastern part of the building, and created a hole in the back wall, according to Casstevens.
Thick grey smoke filled the air for most of the afternoon as firefighters worked to strike the fire.
Several fire departments and 15 law enforcement agencies were called in to help fight the blaze. Eventually, "foam" and hazmat materials units were needed to extinguish the fire, which could not be stopped using only water due to the chemicals at the plant.