PHOENIX - Workers showed up to Burton Barr Monday morning to find out the library was closed.
Video from the Phoenix Fire Department shows thousands and thousands of books drenched after the storm caused a fire sprinkler pipe to burst.
The National Weather Service confirmed a microburst nearby may have lead to the roof's damage.
"Some of [the employees] are just discovering the depth of this," said Lee Franklin, the spokesperson for the City of Phoenix's Library system.
The cleanup process still continued Monday morning. Huge signs read that the library was closed indefinitely. The City of Phoenix Police Department also put up caution tape on the north side of the building.
"The work that they did yesterday on the roof, they were able to get through last night's storm without any additional damage," Franklin said.
PHOTOS: Burton Barr Library experienced storm damage
New concerns for the city were assessing the water damage, seeing if insurance would cover the mess, watching for mold and drying the five stories doused with water.
Employees that went inside had to wear breathing masks.
"We know Burton Barr is the heart," city librarian Rita Hamilton said during a news conference Monday. "Everyone is focused on restoring and reopening [the library] and that is our commitment and goal. We will get services restored here."
Hamilton and a spokesperson for Phoenix Public Library said a majority of Burton Barr's book collection was not affected and staff would be assigned to other locations in Phoenix.