Three people have been burnt to death and another has been critically injured after a car flipped and burst into flames in Sydney's CBD.
The four victims were in a high-performance Nissan GTR that mounted an overpass barrier on Pier Street, flipped onto its roof and caught fire just before 3am on Saturday.
Using fire extinguishers, police doused the car's burning occupants but only one could be removed from the car alive.
That man, a 39-year-old Leichhardt man, is fighting for his life in St Vincent's Hospital with extensive facial and head injuries and several broken ribs.
Two men and a woman who died are yet to be identified.
Superintendent Paul Pisanos said the trio "effectively have been burnt alive".
"The sad part about it is... somewhere across Sydney there are people waking up (whose) sons and daughter haven't arrived home from a night out in the city," he told reporters on Saturday.
Superintendent Pisanos said three young male officers and a female colleague who tried to save the occupants have been extremely traumatised.
"Imagine today they're pondering over their own actions and whether they could do more, which is quite unfortunate," he said.
Police are appealing for any footage of the car from the time of the crash.
It's believed the vehicle travelled down Goulburn Street at speed before the driver lost control and hit an overpass barrier on Pier St.
The car then appears to have rotated mid-air, before it landed on its roof and ignited.
"These, unfortunately, are extreme cases that illustrate that excessive speeds and the manner of driving in built-up areas and any road in NSW can lead to catastrophic consequences," Superintendent Pisanos said.
Several lanes around the Pier, Goulburn and Harbour streets intersection near Darling Harbour remain closed as police try to re-enact the moments before the crash.
Drivers are advised to avoid the area.
