A truck driver killed in a fiery crash amid a snap border closure between South Australia and Victoria hurtled into a waiting line-up of traffic at almost 100km/h.

Steven James Lawrie, 46, died when his Volvo truck slammed into traffic just over two hours after South Australia closed its borders to Victoria following a hotel quarantine outbreak, on February 11, 2021.

A coroner has ruled that the snap border closure “was not a causal factor” in the crash that killed the South Australian man, about 2.20am.

Mr Lawrie’s cabin burst into flames at such an intensity that onlookers had “no opportunity whatsoever” to pull him out of the wreckage.

The force of the smash had pushed the truck it hit forward by 28.5m, causing a domino effect of vehicles crashing into each other.

Tributes flow for truckie Steven Lawrie, who died in a fiery crash on the SA and Victoria border. Picture: Facebook

Steven Lawrie had been working long shifts before the crash.

Mr Lawrie had been doing 12-hour night shifts five days a week from 7pm to 7am and got about four hours sleep the day before he died.

Meanwhile, family and friends had expressed “concerns” about his suitability to drive due to fatigue and inattention.

Ex-wife Margaret Lawrie told the Coroner’s Court when she found out he was driving trucks, she said, “He should never drive a truck because he will either kill himself or kill someone because he can’t stay awake … he just can’t stay awake … he just nods off”’.

Two days before the crash, Mr Lawrie was caught in a “fatigue incident” on a monitoring system where he “closed his eyes and appeared to fall asleep at the wheel of the truck” before he was alerted.

Mr Lawrie’s mentor Robert Dalton, at Allan Miller Transport Training, described him as “ditzy” and lacking in concentration.

“As a passenger in the truck I felt unsafe and think he was a risk on the road,” he said.

“I would describe him as a novice driver. I was of the opinion that Lawrie thought he was a super trucker and knew everything.”

Mr Dalton told the court that four months before the crash, Mr Lawrie was given a written warning for uploading footage of himself driving a truck up the South Eastern Freeway on Facebook.

Mr Lawrie’s cabin burst into flames and onlookers had ‘no opportunity whatsoever’ to pull him out of the wreckage. Picture: 7 News

The aftermath of the inferno. Picture: 7 NEWS

Coroner Simon McGregor found unexplained driver error was the most likely cause of the fatal collision, rather than fatigue or falling asleep at the wheel.

The Major Collision Investigation Unit’s Detective Sergeant Robert Hay found Mr Lawrie was driving about 98km/h with no evidence of braking when his Volvo smashed into a stationary Kenworth truck that had joined a 6km line to pass the checkpoint.