The city of Pasadena’s historic Central Library has been ordered closed pending further review due to seismic safety concerns.

The nearly century-old Mediterranean Revival-style building had just reopened for in-person services following a pandemic closure when the closure order was issued Monday, the city said in a statement.

A recent structural assessment revealed that most of the building is constructed with unreinforced masonry bearing walls that support concrete floors and walls.

So-called URM buildings are known to be a life-safety hazard because they can collapse in an earthquake.

“While Pasadena passed an ordinance in 1993 mandating all URM buildings to be retrofitted, vacated or demolished, no record has been found as to why Central Library was not identified and addressed as a URM building,” the city said.

“This is devastating news for us all,” said City Manager Steve Mermell. “Central Library is more than just a building; it’s where generations of families have grown up, and an iconic building that completes our Civic Center as one of Pasadena’s treasures.”

Central Library was designed by architect Myron Hunt in 1924 and completed in 1927. The building was expanded in the mid-1960s and modified in the 1980s. It is listed in the National Register of Historic Places.

Pasadena’s ornate domed City Hall, also completed in 1927, underwent a seismic retrofit more than a decade ago.