Philip Peckman, the managing director of Dynamic Electrical Constructions, was working back late last night when about 7.15pm he heard the screech of brakes and a loud explosion coming from outside on the Princes Hwy.

``It felt like and sounded like an explosion and I looked out the window . . . at that stage I didn't really know that it was a car,'' Mr Peckman told the Mercury.

``I looked down and there was fire, they had ruptured the gas main that is in the corner of the building and from what I understand it was the gas main that caused the car to explode.

``It forced me back from the window, the heat was pretty intense.''

Thinking that the building was on fire, Mr Peckman phoned the fire brigade and rushed outside.

``I saw things last night that I wish I hadn't seen,'' Mr Peckman said.

``It's is my understanding that two people were trapped inside the vehicle and the vehicle was totally alight and it ended up sitting over the gas main basically, so it was hard for the fire guys to get that sorted out.

``But there was one guy who got thrown out of the vehicle and ended up on the front lawn here, that's what I saw.''

Mr Peckman said another person - a 21-year-old Dapto male - managed to escape from the vehicle with the help of a passerby.

Bloodstains on the footpath show that he staggered for 50m away from the crash scene.

``When I got onto the road I ran into a guy who had a fire extinguisher in his hand,'' Mr Peckman said.

``He said that one guy had got out of the car on fire and he stopped, and he had a fire extinguisher and doused him with the fire extinguisher to extinguish the flames.

``The ambulance was here pretty quick and they took him away fairly smartly.''

The man was taken to Wollongong Hospital with third degree burns to 50 per cent of his body.

Early this morning he was airlifted to the specialist burns unit at the Royal North Shore Hospital in Sydney.