They said firefighters had the flames under control about an hour after arriving to the scene.
"Smoke was coming out everywhere. The sprinkler system [in the facility] was holding [the fire] in check," said Chief Thomas Rafferty of the Leyden Township Fire Protection District.
He said there were only a handful of employees in the facility when the fire stated, apparently fleeing the building on their own power. Rafferty said fire personnel responded to the facility because a fire alarm there went off, but no one called 911.
Leyden Township fire personnel were assisted by fire departments from Northlake, Franklin Park, Bensenville, Stone Park, River Grove, Elmwood Park, Westchester and Hillside.
Rafferty said it's unclear where exactly the fire started in the facility, but said its cause was being investigated. Although the facility was damaged, he said, it's not considered to be a total loss.
Representatives for the PRI Group could not be reached for comment this evening.
Written by Chicago Tribune