A baby boy remains in a critical condition this morning, following a car crash that killed his mother on Friday morning in Hobart.
The 24-year-old pregnant mother was driving home at 1:00am on Friday, after dropping off her partner at work.
Police allege a stolen four-wheel-drive ran a red light, in the central business district, before ploughing into the woman's car.
The mother was 32 weeks pregnant and died at the scene.
The baby was later delivered at the Royal Hobart Hospital.
The woman's two-year-old son was also in the car and was admitted to hospital with minor injuries.
A 15-year-old boy, who was allegedly driving the 4WD, has been charged with manslaughter.
Police said it was likely two other 15-year-olds and a 12-year-old girl allegedly riding in the stolen car would be charged with motor vehicle stealing.
Police alleged the vehicle had been seen twice before the crash, driving erratically at speeds up to 120 km/hour, but said that, in accordance with policy, they had not pursued the car.
The two cars ended up on either side of the one-way arterial street and the allegedly stolen car was badly burnt.
Three teenagers, including a 12-year-old girl, were taken to hospital with non-life threatening injuries.
Commander Glenn Frame said police did not engage in a high-speed chase, as per policy.
"It never followed or chased the vehicle but it turned around and travelled in the same direction but quite some distance behind," he said.
"It's about protecting the public. The last thing we want is police vehicles pursuing those vehicles and putting the public at more risk."
Traffic was diverted around the accident scene for more than seven hours.
Commander Frame said support was being offered to the woman's partner and other people impacted by the incident.