A piece of plywood that flew off a central city roof and injured three people was left unsecured by builders, police say.
On Saturday afternoon, a 27-year-old woman, a man, and a 2-month-old boy were taken to Christchurch Hospital with injuries after being hit by plywood.
The man and woman were discharged on Saturday but the baby remained in hospital in a stable condition until Sunday morning.
Senior Sergeant Phil Newton, who attended the scene, described the incident as a "freak accident".
"But saying that, it probably could have been avoided."
It appeared contractors from C Lund & Son had left building materials, including some pieces of wood, on the roof of DMC House on the corner of Dundas and Colombo streets, he said.
C Lund & Son directors Andrew and Joanne MacGregor said: "Ourselves and our staff are very concerned about the incident that happened on Saturday and our thoughts are with the family involved.
"We are currently carrying out a thorough in-house investigation into the incident and we will continue to co-operate with the MBIE [Ministry of Business, Innovation and Employment] in their investigations."
Newton said the family were in the "wrong place at the wrong time" and were walking past the building when the wood blew off.
He estimated the plywood was 1.5 metres x 1m and would have had "considerable weight to it".
There were more loose items on the building's roof and police and fire crews secured them, he said.
"It was a windy day but it wasn't anything I would call extreme, just a typical sort of norwester."
The patients had already been taken to hospital when Newton arrived, but he understood the woman had been knocked unconscious.
"I think she was holding her baby . . . maybe that protected him a bit but I'm not sure," he said.
Newton did not know when contractors were last on the site but said materials should have been secured.
A health and safety inspector from MBIE was sent to the site.
- The Press
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