'Going far too fast': Resident describes terrifying moments before Bulli Pass fatal

The fatal accident at the bottom of Bulli Pass has left residents and emergency services in shock.

Woonona's Jon Seccombe was driving up Bulli Pass on his way to an appointment in Sydney just before 1.50pm on Friday, February 16, when he was almost hit by a truck speeding down the hill.

"That's the one that almost cleaned me up on a hairpin bend," he told his wife when he later saw photos of the smashed truck and recognised it instantly

The truck was taking a left-hand bend when it came hurtling towards Mr Seccombe.

"It looked to me like it was on the right-hand side wheels, like the wheels on the left side weren't even on the tarmac," he said.

"When he got control of it again the truck sort of jolted in that way as if some of the wheels were off the ground.

"I realised I was in a lot of trouble and I was not going to be able to drive around him ... it probably would have killed me."

He estimates the truck was travelling around 65-70km/h at the time.

The truck wasn't flashing it's headlights, hazards or blinkers, nor was it blowing its horn when it past Mr Seccombe.

"It looks like he was simply going far too fast, and there's an arrester bed just at that particular bend," he said.

The Woonona man, who also holds a truck licence, said if you are in the right gear and driving at the signposted 40km/h speed limit, that "the gears should be enough to stop you".

As it reached the bottom of Bulli Pass the truck veered left into the ramp that exits towards Thirroul and smashed into a BMW 4WD being driven by a 40-year-old woman from Canberra.

Two Sydney brothers, who were passengers in the truck, were thrown out of the windscreen. One of them, aged 43, was killed while his brother Robert Isaako, 40, was airlifted to Liverpool Hospital where he remains in a stable condition.

The 39-year-old truck driver is stable in Westmead Hospital. The woman driving the 4WD remains in Royal North Shore Hospital in a critical but stable condition.

The men in the truck were from Bankstown family-owned removals business DJacks.

A spokesman from the company told the Mercury on Monday that staff were in shock and he was not ready to make any public comments.

The crash ripped open the side of the truck leaving the belongings of a couple, who was moving to Thirroul, strewn across the road.

Speculation has been rife on social media on how the accident was caused.

Despite the fear and shock Mr Seccombe felt as the truck came hurtling towards his vehicle, he's called for calm.

"Before people start jumping to conclusions and saying 'they've got to fix the road, they've got to do this or they've got to put more police booking people' is simply a case of saying accidents happen all over the place. Let's find out the cause of the accident before we insist that the government must do this or that," he said.

"The cause of this accident has got to be scientifically looked at and then solutions made for that."

Mr Seccombe has dwelled on those injured and at the crash scene.

"I feel terribly sorry for those people who have been affected by it and injured by it," he said.

"There is an element of 'there but for the grace of God go I'."

Crash data shows more than a dozen serious crashes between 2018 and 2022 on the notorious road, with a cluster of collisions at the hairpin bend and at the intersection with Lawrence Hargrave Drive.