Officials are investigating a fire that damaged a Waterloo business early Christmas Eve morning.

Firefighters were called to New Star liquor, 315 Fletcher Ave., around 1 AM on Monday (Dec. 24, 2018). When crews arrived, the noticed smoke was showing from all side of the structure, but no flames were visible.

According to information released by Waterloo Fire Rescue, firefighters forced entry into the building by removing the front doors. Once inside, they found a fire in the office area, which was quickly extinguished. Officials said the blaze had already extended into the attic area, so they tore away parts of the ceiling to check for hot spots and to ventilate the smoke.

Waterloo Fire Rescue officials said the blaze caused extensive damage to the office area and surrounding hallway. Cost of the damage was estimated at $25,000.

Investigators are trying to determine what sparked the fire. Officials said one firefighter fell on the ice while battling the fire and suffered a minor injury.