Police have revealed new details about what led to the tragic crash.

Three people have died in a “horrific and tragic” head-on collision that has left two vehicles mangled.

Emergency services were called to Rocky Point Rd in San Souci, South Sydney, to reports of a two-car crash about 12.30am on Saturday.

A white Audi had landed on its roof following the collision, while the top of a blue Camry was found with its roof smashed in.

About 12.25am, police officers attended a home on Second Ave in Gymea, about 8km south of the crash scene, to speak to a 42-year-old man regarding reports of a mental health incident.

As police arrived, however, the man left the scene in a white Audi before police could speak to him.

Soon after, police were called to the crash site.

The 42-year-old male driver of the Audi and both the male driver and passenger of the Camry were killed in the crash.

7NEWS understands the Audi was launched into the air after crashing into a dividing barrier and landing on top of the Camry.

“It was a horrific scene,” Detective Acting Superintendent Graham Hibbs said.

“The circumstances of what has occurred last night, from what I understand, are horrific and tragic.

“We really feel for the families of all three persons who were involved in this incident and their loved ones.”

Three people have been killed in a horror car crash in Sand Souci early on Saturday morning. Three people have been killed in a horror car crash in Sand Souci early on Saturday morning. Credit: 7NEWS

Hibbs said the Camry had been “extremely unlucky” to be involved in the incident.

“I don’t think there were many cars on the road at that time,” he said.

Up to 40 locals raced to the scene soon after the crash to try to help the victims.

“Some of the bystanders rushed over to offer what minimal assistance they could offer in the circumstances,” Hibbs said.

“The engine bay of one of the vehicles had caught alight and they are assisted with putting that out.“

“It was obviously quite a high-impact crash, it was obviously quite a distressing scene for those people.

“It wouldn’t be nice for any person to see that scene that occurred this morning.”

Rocky Point Rd has been shut in both directions as the Crash Investigation Unit assists police with inquiries into the crash.

Anyone with information, including CCTV, dashcam or mobile phone footage, has been urged to contact Crime Stoppers.

SOURCE: https://7news.com.au/news/head-on-car-crash-kills-three-people-in-sydneys-san-souci-c-22325703