Tourists at Auckland's Sky Tower were left terrified on Tuesday when glass on the Observation Deck cracked.
"Was just at the Tower and the observation glass shattered," a witness told Newshub.
"Freaked us out, very frightening."
- Is working on the Sky Tower the scariest job in the country?
- How much wind could knock the Sky Tower over?
- Auckland's Sky Tower blasted by gigantic lightning strikes
The glass floor allows people to walk on it while viewing the street far below.
A SkyCity spokesperson confirmed that the cracked panel was the top layer which is installed to protect the structural layer from foot traffic and the occasional dropped item.
"It sounds like what's happened is that the top protective layer of superficial glass in one of the floor panels of the Observation Deck at the Sky Tower has cracked," SkyCity communications general manager Colin Espiner told Newshub.
"It's been cordoned off and will be replaced."
Each floor panel contains three layers of glass - two layers of sacrificial glass then a 38mm-thick layer of structural glass "as strong as the concrete surrounding it".
"While there was absolutely no danger to the public we will, as part of our normal maintenance procedures, check the rest of the glass floor panels," Mr Espiner says.
Mr Espiner says the Tower is open as per usual.