Investigators have determined the fire at the old Ragsdale tobacco warehouse on South Church Street in Lake City started in the back part of building.
It was one of the oldest buildings in the community, according to city officials.
Firefighters have yet to determine what caused the fire.
Lake City Fire Chief Randy Driggers says the fire started after midnight Thursday and when crews got to the scene flames covered nearly every inch of the building.
Driggers says the warehouse was made of wood and it was empty inside causing the fire to spread quickly.
One firefighter suffered heat exhaustion, but was OK.
Nearly 100 firefighters from Lake City Fire Department, Williamsburg County Fire District, Howe Springs Fire Department, Kingstree Fire Department, Olanta Fire Department, Johnsonville Fire Department, and South Lynches Fire Department helped battle the fire.