On June 26, 1996, during a construction project to install a new roof on the building, a fire started in an unoccupied space under the roof and the fifth-floor ceiling of the Treasury Building in Washington, D.C.. The building is constructed of noncombustible materials, but the roof has been altered and it was the 20th-century wood decking and insulation that caught fire.
Because of the inaccessible location the fire, which went on under built-up roofing material, burned for approximately six hours. During this period, firefighters flooded the roof with several hundred thousand gallons of water, which passed through the building to the basement. Even if the fire hasn’t been extremely wide, severe damages have been recorded due to the large amount of water, smoke and
Plaster ceilings were unstable due to the large amount of water and humidity levels in the building were excessive. As a consequence, objects directly affected by smoke and water damage have been relocated to off-site storage. Although the fire was limited to the north end of this 400,000 sq. ft. building, the corridors and open staircases allowed smoke to permeate the entire structure. HVAC systems throughout the building were also affected and had to be cleaned.
As a result of the fire, some important additions have been made to the emergency plan, that has been expanded to address a range of emergency situations that could impact the building and the collection, including fire, explosion, theft, and power loss.