SALEM - Salem State College shut down its library last night after an engineering report raised concerns about the structural safety of the building.

President Patricia Meservey made the sudden and unexpected decision to close the key campus building midway through the first semester after getting a report earlier in the day from state engineers doing a study on planned renovations there.

"Our top priority is the safety of students, faculty and staff, as well as visitors to our campus," Meservey said in a statement. "We recognize that closing the library will significantly impact our entire campus community. However, it is the right thing to do, and we are taking every step to minimize disruptions."

The dramatic development comes just a week after Gov. Deval Patrick submitted a higher education bond bill request that earmarked $41 million to upgrade the Salem State library.

The building has not suffered any recent damage, nor is it in danger of collapse, an official said. But engineers pointed to several places in the four-story building where they are concerned about its structural strength.

"There was no imminent catastrophe or danger identified. ..." said Karen Cady, a college spokeswoman. "We're really erring on the side of extreme caution."

The decision to close the library presents a major logistical challenge to Salem State, which is already bursting at the seams, an official said.

The library, which will be closed for at least a week, is used by an estimated 3,000 students daily, has offices for 90 faculty and staff, and has numerous computer labs and classrooms. It is the site of the college's learning center, which provides tutoring, and also hosts the instructional media area.

College officials were scrambling yesterday to locate classrooms and offices in others parts of the campus for temporary use.

"We're looking at every nook and cranny that we have," Cady said. "People might be sharing office space, but unfortunately there's not a lot of alternative space available. But we'll just make do."

The report identified a number of areas in the four-story, brick library where engineers are concerned about the "load-bearing level" of the building, Cady said. She said the building, as far as she knows, has not suffered any major damage or deterioration but faces greater demands today than when it opened in 1969.

"The building is 35 years old, and there's just more in the building right now," she said, referring to computer equipment and space that has been converted from study areas to offices. "It's really that the use of the building (is now) in excess of what it was originally designed for."

The Division of Capital Asset Management, which did the engineering study, "became concerned because there were certain readings of the load-bearing-level capacity that they wanted to get more information on," she said.

The college closed the library at 6 p.m. yesterday and canceled classes and meetings there today and in the near future.

Staff and students learned of the closing by e-mails and phone messages. For updates on classroom locations, students and faculty are being directed to the college's Web site - www.salemstate.edu.

The college plans more meetings today to develop its response plan. Although a lot of library material is available online, the plan is expected to include ways students and staff can get books from other area colleges.