The building was heavily damaged by a large fire which began about 19:30 local time (23:30 UTC) on 2 September 2018.
Although some items were saved, it is believed that 92.5% of its archive of 20 million items were destroyed in the fire, though circa 1.5 million items are stored in a separate building, which were not damaged.
First responders fighting the fire were hindered by a lack of water. Rio's fire chief claimed that two nearby fire hydrants had insufficient water, leaving firefighters to resort to pumping water from a nearby lake. According to a CEDAE (Rio de Janeiro's Water and Sewerage State Company [pt]) employee, although the hydrants did have water, the water pressure was very low, due to the fact that the building is on top of a hill. Brazil President Michel Temer claimed the loss due to the fire to be too great to have been predicted.
The National Museum building burning behind the statue of Emperor Pedro II