A spokesperson for the owners of the buildings Totara Dunedin Properties said during demolition work on properties at 380-394 Princes St a "large portion" of facade masonry collapsed into the building zone.
This left a section of the building window arch unsupported and unstable, creating a risk it could fall on to the street.
As a result, Scope Group, which is managing the demolition work, have instated the emergency closure of a section of Princes St to enable the safe stabilisation of the site.
When the Otago Daily Times visited the site this morning a northbound section of the street was closed.
The spokesperson said the section of Princes St would be reopened as soon as it was safe.
The buildings being demolished have been in poor condition for years and dangerous building notices applied at part of the site.
The Dunedin City Council granted consent for their demolition in May and work started last week after a delay due to "minor administrative matters", with the consent being reissued at the end of September.
The work is expected to take about 10 weeks.
