Several roads are closed near the Rideau Centre after a partial building collapse at the old Ogilvy building just before six p.m. Saturday evening.

Nicholas street is closed to traffic between Rideau and Besserer streets -- pedestrians are allowed on the east sidewalk.

Rideau is reduced to one eastbound lane between Nicholas and William.

No pedestrians are permitted on the south side of the street surrounding the buidling.

A public parking lot just west of the building is closed.

Private security is on site, and all closures are expected to be in effect into Monday.

Police say the closures are in place until public safety can be assured.

The century-old heritage building at the corner of Nicholas and Rideau is currently undergoing demolition as part of the Rideau Centre expansion plan -- though the first three floors are to be preserved.

Workers inside at the time of the collapse were able to evacuate safely.

The crumbling wall sent a cloud of dust and debris into the air and onto the road below.

No one was hurt.

A city building inspector was called in to inspect.