It was the second fire to break out at the building in just a few hours. Fire crews from four towns were first called there before noon.
TV5 has been told that flames swept through the roof and walls of the building on Ferry Street.
Then, last night, fire fighters were called back to the scene at around 5:45 pm. After battling the fire, they reportedly called in the fire marshall’s office to investigate.
The building is unoccupied, and officials say they’ve had problems with vagrants setting fires in the structure.