A woman was killed after the vehicle she was in rolled on the Victoria Highway near Bulla on Sunday morning, NT Police said.

Police director of communications Mark Wilton said that about 8:30am Sunday police received reports of a vehicle rolling on the highway about 5km east of Bulla, about 40km southwest of Timber Creek.

Mr Wilton said there were two occupants, a 39-year-old woman who was thrown from the vehicle and declared dead at the scene by an off-duty nurse, and a 19-year-old woman who had to be cut free before being flown to Royal Darwin Hospital in a critical condition.

The Major Crash Investigation Unit is investigating.

Police are asking anyone with information about the crash, particularly those with dash cam footage, to call them on 131 444 (quote reference number P25174133).