The old Trust Building on West Evans Street in downtown Florence caught fire Thursday night.
Florence City Fire Chief Randy Osterman said the fire is contained and under control.
He said it started just after 7 o'clock Thursday and appears to be accidental.
The building was not destroyed and is still intact, only the roof is burned.
Osterman added construction crews were doing some sawing on the roof Thursday in preparation for demolition.
The historic 97-year-old building was set to be demolished next month as Francis Marion University makes way for its new medical school.
Osterman believes the wind must have picked up an ember and started a fire in a pile of debris on the roof.
The City of Florence fire department used four engines and two ladders to fight the fire.
Police shutdown a portion of Irby Street as crews battled the tall flames.
We are waiting to learn how the fire will impact the demolition of the Trust building.
The owner of Wofford demolition said it was set to come down the week of June 16.