A piece of scaffolding blew off the the top floors of the trouble-plagued Auckland Council headquarters, smashing the roof and windows of SkyCity Grand hotel.
Strong winds overnight Saturday are believed to be behind the incident at the Albert St buildings in central Auckland which saw a metal plank blown loose and fall dozens of metres below.
Council and WorkSafe are now investigating what went wrong at the old ASB Tower site, which has been plagued with renovation woes.
Cladding repairs were revealed to be $27 million over budget -- up to $31 million from an estimated $4 million when council purchased the building to be its new headquarters in 2012.
Council's corporate finance and property general manager Kevin Ramsay said that "a metal perforated plank, part of the scaffolding system on the upper levels of the building, came away unexpectedly".