Firefighters were sent to the Buzzi Unicem USA cement plant in Chattanooga, TN Thursday morning after a blaze ignited at the facility.

“Around 6:45 a.m. Thursday, staff members at Buzzi Unicem USA’s Signal Mountain plant noticed smoke coming from a machine that grinds up rock,” the Chattanooga Fire Department wrote in a Facebook post. “Hydraulic oil caught fire and the workers put it out several times, but it kept reigniting, so they alerted the CFD.”

After crews arrived at the scene, a second alarm was issued for additional firefighters and resources. CFD said a “slight fire” was observed between metal paneling and the grinding equipment during the response.

“The plant’s staff got a majority of it knocked down with fire extinguishers but there was still some trapped in insulation so firefighters overhauled the area to make sure everything was fully extinguished,” the fire department wrote.

Operations were expected to resume at the site several hours after the flames were put out, CFD stated.

Timothy King, Safety and Health Manager at Buzzi Unicem USA's Signal Mountain plant, emailed Powder & Bulk Solids on Monday to clarify details of the incident:

"On the morning of March 25, at 7:00 am, smoke was observed coming out from under the aluminum siding which covers the insulation of the mixing chamber under the Cone Valves and above the Raw Mill.  On investigation, it was found that a hydraulic line fitting to the North Cone Valve had failed causing hydraulic oil to leak down into the insulation between the siding and the mixing chamber.  Due to the residual heat in the mixing chamber, the insulation that had become saturated by the leaking hydraulic fluid combusted and a small fire resulted. 

The onsite workers extinguished the fire with two fire extinguishers; however, the fire reignited in one spot where the siding was open to the atmosphere.  Per the plants policy of only fighting fires in the incipient stage and as a precautionary measure, the local fire department was contacted.  Upon the fire departments arrival, the siding was removed and the fire was extinguished.  From the time of first notice of the fire to complete extinguishment, was twenty-five minutes."

No injuries were reported during the fire.