It sounded "louder than a demolition derby," yet the driver who caused the fatal pile-up on Sydney's M4 claimed he had no idea and drove away.
But Francis Omigie must have known the catastrophic trail of destruction left behind him that killed a tradesman on his way to work, a judge found.
The 55-year-old has been jailed for at least two years and two months and will first be eligible for parole on April 4, 2023.
"I wish I never got out of bed that day," Omigie said of the highway chaos he caused in May 2019.
Irishman Francis Shanley, 36, died in the crash involving at least eight cars and a truck at the Church Street off-ramp in Mays Hill, while about 200 metres of debris was left sprawled along the motorway.
"It is, without doubt, a deeply tragic case," Judge Jane Culver said on Thursday in the NSW District Court.
The part-time electrical trades assistant was driving a green Toyota Echo on his way to work before he changed lanes and suddenly stopped in front of another vehicle.
He then ignored that motorist's flashing lights and honking horn and continued to merge.
Omigie gave a number of inconsistent versions as to why he forged on so recklessly in near peak-hour traffic.
He posited that mechanical defects had distracted him while he moved towards the breakdown lane.
But Omigie failed to raise car faults in many key moments and had told the previous owner there had been no vehicle problems thus far, and this was rejected.
His text message about 25 minutes after the crash to his wife spoke of "three near misses," and "I better move on with my life before I end up dead".
The idea these were purely coincidental and an attempt to garner sympathy due to problems in the relationship were also dismissed.
The judge ultimately found it was a "selfish disregard of drivers around him" as he belatedly moved to exit the highway before incurring a toll.
He said he found out the next day about the crashes when police contacted his wife.
But witness accounts of the "extremely loud noise," including one who said the crash sounded like metal "louder than a demotion derby," prompted the judge to believe Omigie heard something of the calamity.
"He actually knew when he left the scene that his car was involved in impact of such enormity that he must have known death or grievous bodily harm was occasioned," she said.
Omigie had shown genuine remorse in statements that he was "heartbroken," after what had happened to "another human being, a soul like myself," the court found.
He also helped his case by not disputing he had done the wrong thing by attempting to merge and admitting to stopping.
A jury earlier found him guilty of dangerous driving occasioning death, and failing to stop and assist.
Outstanding charges will be dealt with, or potentially withdrawn, in November.
A handwritten letter to Mr Shanley's Australian fiancee, Broc Nicholson, expressed understanding of the enormous pain she must be feeling from the loss.
A statement by Ms Nicholson - who watched the sentence proceedings via video link - expressed how she was no longer the same person after the tragedy completely transformed her life.
Omigie's head sentence is three-and-a-half years.