SLIPPERY ROCK TWP, Lawrence County — Firefighters spent about three hours putting out a fire at a manufacturing facility on Route 422.

The fire broke out after midnight at Advanced Feedscrews located a few miles from the Butler County line.

Chief George Johnson of the Slippery Rock Township Volunteer Fire Department said that the electrical fire caused minimal damage.

When firefighters arrived on scene, all they could see was smoke — there was no visible fire. Crews spent some time looking for a source of the smoke, and eventually found that the fire started in the ceiling and spread through the walls. Then, they got to work putting the fire out.

“Firefighters made an excellent stop to keep the fire from spreading,” Johnson said.

He said the building is constructed of steel and the walls contained fire-retardant insulation, which kept the fire from spreading quickly.

Besides a few ceiling lights, insulation and walls, Johnson said there was not much damage to the building. All of the machinery was intact. The company manufactures and rebuilds feedscrews and barrels.

Seven employees were in the building at the time, and they reported the smoke. Nobody was injured in the fire.

About 30 firefighters responded to the fire. In addition to Slippery Rock Township, firefighters from Hickory Township, Scott Township and Portersville, as well as Medevac Ambulance, responded to the fire. Crews went back into service shortly before 3 a.m.