The Smithsonian’s Natural History Museum reopened after being shuttered Thursday morning because of emergency repair work.

The museum is in the midst of a major construction project, a five-year, $48 million makeover of its southeastern wing, which includes the famous dinosaur hall. Randall Kremer, a museum spokesman, said that contractors working on that renovation on Wednesday night inadvertently disabled several cables in a control room affecting many key functions at the museum — including telephones, computers, the audiovisual and security systems in each exhibit and the cafeteria.

Becky Haberacker, a museum spokeswoman, said that the museum’s phone and computer network were shut down entirely Thursday morning. Kremer said that the security of exhibits would also have been compromised if the museum had opened to visitors and that exhibits that rely on moving parts or audiovisual displays may not have functioned.

Kremer said the museum’s senior staff was made aware of the problem just before midnight and called in an outside firm that is on contract with the Smithsonian to do repair work.

The contractors and Smithsonian employees worked all night to fix the problem, Kremer said. Shortly before 5 a.m., the staff announced that it would not be ready to open to visitors at the usual time of 10 a.m.. By noon, the problem was fully resolved and the museum opened its doors.

“We don’t open the museum if there’s any sense that we can’t do our job,” Kremer said. “The museum was not functioning the way it has to function in order to present to what would have been hundreds of visitors.”

Collections in the museum were unharmed, according to a message on the Smithsonian’s Twitter page.

The museum, which opened in 1910, has millions of visitors a year.