Multiple fire departments battled a fire Wednesday morning inside an apartment building at 108 S. Main Street in downtown Columbia across from Thai House. The Columbia Fire Department responded to the scene about 10:10 a.m., with the Waterloo, Dupo, Cahokia and Millstadt fire departments providing mutual aid.

Fire crews blocked traffic on Main Street near the structure as they worked to contain the blaze. Main Street was reopened to traffic at 11:30 a.m.

The initial reports were of heavy smoke in an upper level apartment area of the multi-level structure with visible fire in the rear of the building. The apartment was unoccupied at the time the fire broke out, a fire official said.

The cause of the fire was believed to be electrical in nature.

The lower floor of the building is home to Columbia Optical Center and a vacant business space.

Columbia Fire Chief Mike Roediger said black smoke was showing from the upper part of the building upon firefighter arrival.

Thankfully, a quick knockdown resulted in only one apartment unit of two in the upper portion of the structure being damaged. The hallway between the two units and the other unit were spared from damage, Roediger said.

The two business spaces on the lower level sustained only minor smoke and water damage, Roediger added.