The witnesses spoke to the Herald about the ordeal yesterday as the victim recovered in Auckland City Hospital.
The woman was running down Richmond Rd in Grey Lynn about 10.30am on Sunday when the truck began reversing towards her with its back tray down. The tray pinned the woman against a wall.
Hell Pizza owner Edward Chen heard a loud bang, followed by a woman screaming "help, help, help".
"When I went there to have a look I saw three or four people around the lady. Her legs were totally broken."
One contractor said of the scream: "I've never heard anything like it."
Police are investigating the incident but say that it is too early to determine if any charges will be laid.
They initially told media the woman had lost one leg and that the other had to be "surgically removed". Yesterday spokeswoman Noreen Hegarty issued a statement saying that information was incorrect.
"Police accept the information passed to you is incorrect and apologise for any confusion it has caused."
The victim's family said she was "recovering".
They were not ready to speak further about the incident and requested that the specifics of her condition be withheld.
The driver of the truck has been stood down pending the investigation.
It is understood the driver was picking up empty mail cartons from the Grey Lynn branch of NZ Post, which was closed, when the incident occurred.
The CourierPost truck is owned by a contractor for Express Couriers Limited. An employee of the owner was driving at the time.
ECL spokeswoman Ana-Mari Gates-Bowey said: "The driver is extremely distressed and is receiving support from ECL and his family."
Chief operating officer Paul Trotman said ECL was investigating the incident and had conducted interviews with the contractor and his employee.
"We recognise this is a traumatic time for everyone involved."
- additional reporting Anna Leask