Jim Davis/Globe File
The Boston Athenaeum, the landmark membership library on Beacon Hill that is more than 200 years old, has sent thousands of books to a specialist for freeze-drying after a water leak flooded the building on Monday.
Library officials said today that the leak caused tens of thousands of dollars in damage. While stunned by the incident, they were also relieved because no truly historic items had been destroyed.
"It could have been a spectacular disaster," said James Reid-Cunningham, the Athenaeum's chief conservator.
The cause of the leak still hasn't been determined, but it did happen on one of the coldest days in years so frozen pipes are a suspect.
The flooding started on the first floor of the building on Beacon Street. "It was like Niagara Falls," said librarian Paula D. Matthews.
The flooding spread from the elegant Long Room, which overlooks the Old Granary Burying Ground, and to the Newspaper Reading Room, the Bow Room, and the Childrens Library. The water was ankle-deep and seeped into stacks of books on lower floors, officials said.
The Athenaeum was founded in 1807 and is one of the oldest independent libraries in the United States. It will be closed for the next few days, officials said.