A section of the ceiling on the ground floor of Montreal's Grand Bibliothèque collapsed just after noon Wednesday, just moments after employees had been safely evacuated.

A crack had appeared in the ceiling a few minutes prior to its collapse, said the library's communications director, Geneviève Rossier.

"Fortunately, no one was present under the structure because we were able to move everyone out," Rossier said.

Employees noticed a rift had appeared a few minutes prior to the collapse. Library employees and patrons were immediately evacuated and no one was injured when the roof came down. (Facebook)

Rossier explained that the part of the ceiling that caved in had just recently been constructed, above the renovated library's newspaper and magazine section.

Building engineers are now doing a thorough inspection of the building, Rossier said.

"The section which collapsed was not part of the original construction," said Quebec Culture Minister Luc Fortin, who will visit the site Thursday to assess the damage.

The Grande Bibliothèque remains open to the public, except for the newspaper and magazine section.