PLYMOUTH, Ind. - Firefighters are investigating an early morning fire at a plant in Marshall County.

It started Thursday morning at AK Industries on Pidco Drive, which makes septic tanks.

Plymouth fire chief Rod Miller says a static spark caught a pan of resin on fire in the corner of a cleaning room where they clean parts.

The fire was contained to that area, but the fire chief says it caused significant damage.

One employee was treated on the scene for smoke inhalation and released.

Miller says the fire should not affect business at the plant.