The Dunedin City Council says it remains confident the Wall Street mall is safe, despite fresh tests after another glass failure in the council-owned building.
Council contractors yesterday completed tests of the glass ceiling panels to check the integrity of a protective film added to the ceiling in 2012.
The film was designed to hold broken glass in place if a panel shattered, and was added after a ceiling panel did just that in 2011, showering two members of the public below it in debris.
In a second incident in 2015, a 6m by 3m decorative glass panel on the building's facade split into two pieces which fell, minutes apart, on to a veranda below.
Nobody was injured, but a second large pane of the decorative facade - immediately below the one that fell - was also damaged.
Yesterday, council city property manager Laura McElhone confirmed a third incident - also involving a glass piece of the building's facade - had occurred soon after she began her new city property role late last year.
The glass panel had also ''shattered into small pieces'' and fallen on to the entrance veranda below.
No-one was affected, but the incident prompted Dr McElhone to review previous work on the building's glass, she said.
The review raised questions about the longevity of the film protecting the building's roof glass, which has been in place since 2012, she said.
''The advice we got was that we should destruction test it to give absolute confidence that if a panel failed, the film would hold the full weight in place,'' she said.
Those tests were completed yesterday, but work to fix the glass facade at the front of the building would be carried out next week, she said.
The new panels would be heat-treated and did not need the same protective film, ''and there is no risk to the public if they fail because the pieces are caught by the veranda'', she said.
''We are very confident that this doesn't present a safety issue for the public,'' Dr McElhone said.
''The tests will help us to ensure that it stays that way into the future.''