The man behind the wheel of a hired 4WD that lost control on a bend and rolled in Kakadu National Park, killing himself and two others, was not experienced with NT road conditions, police say.
Seven young people - all believed to be members of the Top End's Bangladeshi student community - were travelling from Jabiru to Cooinda in a Toyota Landcruiser on Saturday afternoon when it crashed on the Kakadu Highway.
Four women were injured in the crash and are in a stable condition in a Darwin hospital.
The driver has been confirmed by police as a 29-year-old Bangladeshi man, but the nationalities of the other six passengers have not been released.
"The driver was pretty inexperienced in Territory conditions. He was in a vehicle he was not familiar with - it was a hire vehicle," Acting Assistant Commissioner Tony Fuller told reporters in Darwin on Sunday.
"He's lost control in a large bend and ended up rolling the vehicle.
"One person was ejected from the vehicle."
Speed may have been a factor and investigations are underway to determine if all passengers were wearing seatbelts, Act Asst Fuller said.
Two CareFlight aircraft were sent to the crash site, described a spokesman as "horrific", along with doctors and nurses.
A second vehicle carrying family members was believed to be in convoy with the Landcruiser.
The four injured women - three of them aged in their 20s - were flown to Royal Darwin Hospital and arrived at 5pm on Saturday.
All four are listed as stable, a hospital spokeswoman told AAP on Sunday.
The women are aged 23, 24 and 26, while the age of the other women is unknown at this stage, the spokeswoman said.
Up to 100 people from the Bangladeshi community are keeping vigil at the hospital for the four women, the ABC reports.
Act Assistant Fuller reminded drivers to take extra care when behind the wheel in the NT.
"Someone that's used to driving in the city and then suddenly out on a major road with a high-powered 4WD, with the extra weight, and is just not used to those sort of vehicles, it becomes very dangerous," he said.
The NT News reports the highway was closed for several hours just north of Cooinda Lodge but has since reopened.
Act Asst Fuller urged all drivers to take care returning from Easter breaks, with the road toll for the Northern Territory already at 15 for 2018.
He also urged passengers who may feel uneasy with a bad driver to not get in the car.
"We've already lost six passengers in vehicles out of the 15 people killed so if you don't think the driver is a safe driver don't get in the car, if they've been drinking, just don't get in."
