"It just sounded like pots and pans," a resident who came to the aid of those injured said.
"I thought someone had dropped dishes and then I looked out my window and thought, 'What do I do?"'
The woman rang emergency services and relayed instructions to her flatmate who provided assistance to the unconscious 18-year-old woman in the back seat of the car.
Another resident said she arrived on the scene from her house to find those involved in the crash "massively in shock".
During the commotion the driver of the car left the scene but arrived back after a short time in the company of a female and a police officer, she said.
St John rushed six people, including one who was in a serious condition, to Dunedin Hospital in three ambulances, spokesman Ian Henderson said.
A Dunedin Hospital spokeswoman said she could not release any condition updates.
Police are still trying to piece together the crash and would not comment on whether charges had been laid against the driver of the car.
The crumpled car could be seen on the footpath against a wall at the scene along with a ute with minor damage.
The ongoing investigation would look at whether speed or alcohol were factors in the crash, as well as whether the six injured people were wearing seatbelts.
Police were working towards contacting the next of kin of the 18-year-old woman.
It has been a week of tragedies on New Zealand roads, with five fatal crashes in six days.
A logging truck and ute collided near Rotorua on State Highway 30 yesterday about 1.30pm, leaving one man dead and five injured. The identity of the dead man has not been released.
Terry Henry Munday, 63, died in a car crash near Ashburton about 11pm on Friday and motorcyclist Shannon David Stewart died on Sunday in Christchurch when a van did a u-turn in front of him. It has since been revealed Mr Stewart was a former Pike River miner who escaped the 2010 mine disaster by less than an hour.
In the early hours of Sunday morning, 14-year-old Rangimaria White died in an alleged hit-and-run as she attempted to cross a residential Opotiki road. Police have not released information about whether the driver has been apprehended.
Facebook page launched
A Dunedin man has kicked off a social media page in light of a spate of serious car crashes in the city.
Kris Palmer started the "Dunedin car crash" group on Facebook in the early hours of this morning after seeing the "mess" at the traumatic crash scene.
Mr Palmer said he created the public Facebook page to help people share information about crashes in the area. "There [have] been a lot of crashes lately," he said.
This morning's fatal crash comes just days after a hit-and-run in Dunedin in the early hours of Sunday morning where a 17-year-old youth was dragged along George St.
The incident occurred about 2.30am and the 19-year-old driver has since come forward with an apology.
A car carrying Dunedin students was torn apart in a horrific crash in March on Signal Hill Rd. All six men, aged in their early 20s, were taken to hospital.
One of the passengers was in the boot and suffered serious injuries.
(Additional reporting from Lauren Priestley of NZME News Service)