As library support staff arrived at work at the Mill Woods branch Wednesday morning, they discovered three 50-lb. lighting fixtures had crashed to the ground in a common area.

The branch was closed immediately for safety reasons.

"We are very glad that this happened while the facility was closed and we are working to make sure this doesn't happen again," said Jason Meliefste, branch manager of Facility & Landscape Infrastructure.

Mill Woods library

The Mill Woods library closed Wednesday when three light fixtures fell from the ceiling. (CBC)

One of the supports for the lights gave out, causing a chain reaction with the other two lights connected to the fixture, Meliefste said.

The incident is still under investigation. But it appears the anchors for the light fixtures failed due to "construction workmanship" at the library, which opened in July 2015, said Meliefste.

The Edmonton Public Library website says the Mill Woods branch will be closed through March 6.

Meliefste said the contractor has been "absolutely co-operative," and because the incident stems from a construction deficiency the contractor will bear all costs associated with the repair.

The Meadows branch and Whitemud Crossing are the two closest locations for those hoping to use alternative city libraries.