The death of an intellectually disabled man who fell 40m down a bank could have been prevented, the coroner has found.
The report into the death of Darryl Kitto, 47, details his fall down a steep embankment in a car park area overlooking the Rakaia Gorge.
He died as a result of his airway being obstructed by inhaled vomit, which occurred due to a cervical vertebrae fracture, coroner Sue Johnson found.
Kitto was under the care of community mental health service Emerge Aotearoa. Two caregivers were with him at the time of the incident, Kathleen O'Shea and David Smyth.
The 47-year-old was on the way back from Ashburton to his Emerge home in Christchurch with his caregivers.
They took a scenic route back to Christchurch, and driving past the gorge, Kitto asked if he could have a look as he wanted a photo of himself for his sister.
O'Shea, who had cared for Kitto for a year, took a photo of him standing at the edge of the carpark area, on an embankment with no guardrail. He wanted another photo with the river behind him.
As he was "too tall to be in the photo and have a view of the river in it", he stepped down to a lower mound on the embankment.
O'Shea said she must have taken a couple of steps back to take the photo.
"She looked down at her phone and then heard a noise that made her look up and she saw Mr Kitto stumbling like he had lost his balance."
O'Shea started to move forward to grab him.
"She thought he went head first over the bank behind him. She ran forward to see where he had gone, but could not see him."
Smyth said he saw Kitto start to fall backwards, and said Kitto landed on his back then rolled off the lower mound and over the edge - about 30 to 40 metres down the embankment.
Both caregivers were not aware of how steep the slope was, and there was no evidence to support they knew of the danger he was in.
Johnson ruled his death was also preventable.
"He was standing on the lower mound when he fell. There were no signs in the car park warning of the steep drop off from the lower mound and no fence to prevent him from falling down the embankment."
A forensic pathologist who did a post mortem examination said Kitto had a spine fracture with spinal cord crush consistent with a tumbling fall from a height.
"In his opinion the spinal fracture caused him to vomit and the vomit obstructed his upper airway and this was the direct cause of his death."
Although Kitto's sister said he was "slightly clumsy", the exact reason why he stumbled remains unknown.
Johnson endorsed NZTA's recommendation to install a fence around the perimeter of the carpark.
"I find that he died as a result of his airway being obstructed by inhaled vomit... His death was an accident."
Johnson extended her sincere condolences to Kitto's sister for the loss of her brother.