LEE’S SUMMIT, Mo. — Investigators are working to determine what caused a fire to break out at a Lee’s Summit warehouse Thursday night. 

Around 11:47 p.m. the Lee’s Summit Fire Department was called to a fire at the Performance Food Group warehouse at 290 SE Thompson Drive.

The incident was first reported by employees coming into work, when they saw fire in a refrigerated semi-trailer parked against the dock door of the warehouse. 

When firefighters arrived on scene the fire had completely engulfed the trailer. 

Investigators say the fire started in the trailer’s refrigeration unit and spread to the building through the open trailer door. Firefighters say the dock door was closed, slowing the fire’s spread. 

Heat damage to the door caused heavy smoke to enter the dock area, but firefighters contained the fire before it could spread inside.

The building was evacuated and no injuries were reported. Crews had the fire under control by approximately 12:25 a.m. Once the fire was under control, crews ventilated the facility to remove the smoke from the dock area.

The fire caused extensive damage to the trailer and dock door, as well as heat damage to another trailer in the dock next to it. The inside of the dock door and the wall above it sustained heat and smoke damage.

LSFD says the refrigeration unit was running, but the trailer was empty at the time of the fire. Investigators are working to  determine what caused the fire in the refrigeration unit.

Jackson County Environmental Health is evaluating smoke damage in the building to determine the integrity of the food that was being stored at the warehouse.