Burlington, Wisconsin, USA 06 July 2017 -- (From news reports) -- Fire investigators are working to determine the cause of a fire that broke out June 30 at the Packaging Corp of America facility.

The call went out at 12:30 p.m. with a report of smoke coming from beneath water and gas pipes in the facility.

The first crew that arrived helped evacuate employees from the commercial building, fire officials said. No injuries were reported.

Multiple fire departments from three counties responded to the scene to assist, among them: Lyons, Lake Geneva, Delavan, Rochester, Tichigan, Kansasville, Wind Lake and Wheatland in addition to the city and town of Burlington fire departments and the Burlington Rescue Squad.

At one point, City of Burlington firefighters went onto the roof of the facility to fight flames that had apparently climbed up through a silo.

An employee said the fire started as a result of paper left on a conveyor belt during the lunch hour. Friction with other parts of the conveyor sparked the blaze, he said. But fire officials, as of early Friday evening, had not confirmed a cause.

"At this time, the origin of the fire is undetermined," City of Burlington Fire engineer Justin Benko said.

Fire crews spent nearly six hours on scene, containing the fire, Benko said, then conducted an overhaul and finally worked with plant personnel to make sure everything was safe before fire crews left.

Inside at the site of the fire, about 4 inches of standing water from sprinklers and firefighters fighting the blaze was visible.

"Everything was controlled rather quickly," Benko said. "But then you have to get everything intact and in running order before we (leave). We stayed as a precaution."

The Racine Fire Bells unit based at Lake Geneva and We Energies crews assisted at the scene.

According to the company website, the PCA Burlington plant is a full-service supplier of corrugated shipping containers, high-impact graphics packaging, point-of-purchase displays and point-of-sale packaging.