A water line break over the weekend flooded an entire floor of the Rochester Public Library downtown and damaged two more floors below, forcing the facility’s closure at least through Monday.

The main line broke midday Sunday, shortly before the library was to open for the day, on the third floor of the building on 2nd Street SE., according to the Fire Department.

The third floor “was totally flooded, while the first and second floors were approximately 40% affected by water,” a department statement read.

Most of the library’s 440,000-plus collection of books and other materials was undamaged, according to library administration.

Fire personnel used squeegees and vacuums to collect the water and put tarps in place to protect as much of the library’s interior as possible.

Joining firefighters in the response were city and state workers who “chipped in to remove water and help salvage items,” according to a statement from library administration.

The leak was associated with the building’s water softener system, but fire officials haven’t given further details about how it happened.

The library’s short-term closure will allow contractors to assess and repair the electrical, mechanical and structural damage.

In a stopgap measure, the library’s bookmobile was scheduled to be parked on 1st Street SE. from 9:30 a.m. to 5 p.m. Monday for patrons to check out materials and pick up any items on hold.