Emergency services are at Morningside train station in Auckland where a car has been hit by a train shortly before 4.30pm.
A Herald reporter at the scene said it appeared the car had been sitting on the tracks in an area marked by yellow lines when the train hit it "dead centre" on Morningside Drive.
The blue hatchback then spun off the tracks and its airbags deployed, she said.
A woman was freed from the car by fire crews shortly after 4.45pm and taken to Auckland Hospital in a serious condition.
Jess Angove, who co-owns a local cafe, was standing around the corner when she heard the crash and went to see what had happened.
When she arrived at the scene people told her the woman was dead, but when she went to check she saw she was alive, but barely conscious.
"I managed to get in the car and just hold her."
Angove said she was trying to support the woman's head in case she had neck injuries.
A witness earlier said they had seen a child in the front passenger seat, but Angove said this was not the case and the woman was alone in the car.
Early information from the scene was that the barrier arm was down and the lights were flashing when the vehicle has driven through, police said.
Ellen Sorkin, 24, was heading home in an uber when she saw the incident unfold as the car pulled out of Health and Fitness Sport centre on Morningside Drive.
"I was in an uber and our car was at the front of the queue.
"She swerved and the arm was already down but the barrier only covers the direction of the traffic so she went through."
All trains have been stopped and road closures were being put in place, with no entry from St Lukes Rd or New North Rd.
Diversions will be put in place and motorists were asked to avoid the area.
Two fire trucks, police cars and an ambulance were at the scene, which had now been cordoned off.
Auckland Transport said train passengers should expect cancellations and delays on the Western line due to an emergency services incident at Morningside.
An eye witness on the train told the Herald he had seen fire crews using the jaws of life to try and remove the woman from the car.
He said no one was allowed off the train, which had been on its way to Swanson from Britomart.
Serious Crash Unit is at the scene and is expected to be there for sometime, police said.
There have been several serious accidents at the rail crossing. In January last year a 24-year-old man was killed while walking across the tracks.
In 2013, a 22-year-old woman suffered horrific injuries after her wheelchair became stuck in the crossing.
Two bystanders rushed to help when they saw a train approaching, but could not free her wheelchair in time and had to throw it out of the train's path.