(Photo by Russ Mitchell) Members of the Spencer Fire Department position themselves on the roof to fight a fire at the RR Donnelley printing facility in Spencer. Sparks from a welding and pipe-cutting project may have landed on insulation and started the blaze. [Order this photo]

The Spencer Fire Department was called out just after 5 p.m. Wednesday to the plant near East Seventh Street and Third Avenue East in Spencer.

The city's fire chief, Doug Duncan, thinks sparks from a rooftop construction project caused the fire. The project's contractors spotted flames and called the fire department.

"They're putting in their new pollution-control device and they need to run some pipes across the roof," Duncan said. "They were cutting and doing some welding on the roof line to support it. They caught some insulation on fire underneath there."

The fire spread to insulation in an interior wall.

"I've got crew inside opening the wall up and I've got crews on the roof," Duncan said. "They had to open up the roof a little bit."

By about 6:15 p.m. Duncan thinks firefighters had the fire extinguished. They remained on the scene to make sure the fire didn't spread to other parts of the RR Donnelley roof.

The fire damage is expected to be minimal, though the company will have to patch parts of the roof that were sawed into by firefighters.

"It was a fairly small, contained area, but it could have worked its way across the roof," Duncan said. "So fortunately, they found it quick enough and let us know."

The Spencer Fire Department was assisted at the scene by the Spencer Police Department and a Spencer Ambulance crew.