Neither was believed to have been wearing a seatbelt at the time of the accident on Buckland Rd.
Another girl, believed to be a friend of the victim, expressed her hope the driver would pull through.
Addressing the dead 16-year-old, she wrote: "Just saw you on Friday night, girl? fly high, gorgeous! You're in a better place now? hope the driver is okay as well."
The early-police morning chase started after a resident of Hill Rd, Papatoetoe, reported seeing someone breaking into a car about 3.30am.
Police arrived four minutes later and tried to get the driver to pull over.
When that didn't happen, they pursued it around the streets of Papatoetoe and Mangere.
However, by the time of the fatal accident, they had already given up the chase, a police statement said.
"The pursuing officer lost sight of the stolen vehicle and came across it when it had crashed into an oncoming vehicle on Buckland Rd."
A Buckland Rd resident, who lives just past the Wickman Way intersection, was sitting on her deck with family about 3.45am when she saw a car speed past their property.
"It was going really fast down the middle of the road -- over 100km/h, maybe even over 120km/h. It was really loud, revving lots like a car does when it's really going. We jumped up and saw it cross over the centre lane and crash into a vehicle that was coming from the other way."
The police car arrived moments after the crash, she said. "Then heaps [of police] came and everyone came out of their houses to see what happened."
The resident said it wasn't the first crash she had seen on the long strip of road, which has a 50km/h speed limit.
After the crash, her partner went to the car with the two girls inside while she went to check on the other vehicle.
"He was a Tongan guy, around his 40s, who lives around here. He was driving home from Onehunga. He said there was nothing he could do; he couldn't get out of the way in time."
Senior Sergeant Duncan Hall said the driver of the other vehicle was shaken but uninjured.
Mohammed Ayaz, who lives right where the crash happened, said he went outside when he heard the collision.
He saw a white SUV Toyota Parado smashed in the front and a white Nissan Pulsar car with a blue stripe smashed in the back and left side.
"There was a fair bit of damage done to both the vehicles," he said. "There were lots of police and an ambulance, and fire engines. It was hard to work out what had happened."
Another resident of the street, Teresa Morgan, said she woke up to the sound of a loud crash.
"There was a loud bang ... I thought a car had crashed into a pole. We went outside and it was already all over. The car had crashed into a fence and was really smashed up. I saw seven police cars, two fire engines and an ambulance. Heaps of people were out on the street but the police told us all to stay back."
The Independent Police Conduct Authority is investigating, as it does any police pursuit which ends in tragedy.
A police spokeswoman expressed her condolences to those involved, but said the incident showed the tragic consequences that could happen if a driver failed to stop for officers.
"These incidents are also devastating for our staff and it is the last thing our officers go to work for."
Nationwide, about 2000 drivers are caught fleeing police each year.
Police Association president Greg O'Connor has said there is no right answer for dealing with fleeing drivers.
"Those numbers only include drivers who were caught ...
"It's an issue police forces and governments around the world are grappling with."
Mr O'Connor said most pursuits that ended in an accident happened within 30 or 40 seconds of a chase beginning.
