A man has driven a car directly towards a packed North Shore Hospital emergency department (ED), crashing into bollards right outside the door.
RNZ understands he had been at the hospital's ED a short time before on Saturday night.
Sarah Dalton, executive director of the Association of Salaried Medical Specialists, said there were a lot of patients waiting by the door when the crash happened.
The union had been talking to doctors about it.
"We know that they're incredibly grateful that there were bollards in place because if there hadn't been there would have been considerable numbers of people hurt," she said.
North Shore Hospital said the bollards prevented the car from making contact with the building - which is what they were designed to do.
Dalton said health workers were worried about security at emergency departments around the country. There was also concern about the long waits, particularly for acute mental health patients.
"I do want to emphasise that we know that most people needing to be admitted for mental healthcare are not dangerous and are not violent," she said.
"But nonetheless those very busy, very overcrowded EDs are utterly unsuited to the needs of those people."
A 42-year-old man has been charged with reckless driving, intentional damage, threatening to kill and possession of a knife in connection with the crash.
Last year, the hospital said it was increasing security after an incident in which one patient abused a nurse and then punched another patient who stepped in to help.
