The Copthorne Hotel in Christchurch's central city has collapsed today.
The nine-storey building on Colombo Street collapsed about 1.30pm, Brett Watkins of southern police communications said.
Nobody was injured in the incident.
The middle of the building collapsed, leaving two outside walls standing, he said.
"At this stage we do have the area cordoned off in case those two sides do fall down."
One News reporter Lisa Davies said an eyewitness saw two demolition workers running away from the building as it went down.
The Copthorne is in the process of being demolished.
There was no obvious trigger for the collapse, Mr Watkins said.
Specialist engineers would inspect the site and make a decision on what to do with the remains of the building, he said.
People are calling for free testing so people would drive safely.