A lorry driver who suffered an uncontrollable coughing fit drove over a car and killed two grandparents, their baby great-grandaughter and her mother.
Astonishingly, when the truck stopped 100 yards away, the driver didn't realise what he'd done.
Owen Davis told a motorist who stopped to help: "I'm just pleased I haven't hit anybody."
Mr Davis, 42, was arrested on suspicion of causing death by dangerous driving but was later told he would not be prosecuted after his story was backed up by medical tests that showed he had a whooping cough infection.
Robert Reed, 75, his wife Margaret, 74, their one-year-old great-granddaughter Destiny and her mother Natalie Simpson, 18, died in the collision between his Renault Scenic and Mr Owen's Volvo lorry in April last year.
An inquest heard how his lorry-load of Tarmac went over Mr Reed's people carrier, through a hedge, up a bank, and on to the golf course near Seaham, County Durham, while he was unconscious at the wheel.
Mr Davis told the inquest in Crook: "I was coughing. I tried to get a breath in. I started to panic. There's no lay-by, I'm going to have to park in the road and the next thing I remember is peace and quiet."
Mr Davis, who is married with two sons, said he remembered in detail the moments leading up to the crash on the 40mph road, adding: "I had the radio on, I was listening to Aha's Take On Me and I was tapping my finger. My speed was increasing. On the clock I saw I was doing 46 and I slowed down to 43."
It was then he began to cough for about six seconds before he passed out.
He added: "I got out of the lorry, I was dazed, I didn't know what had happened. I had a pain in my stomach where I had hit the steering wheel. I wanted to lie down."
Someone then told him his 15-ton lorry had hit a car. When Mr Davis asked what had happened to the other driver he was told: "Yeah, yeah, he's fine. He's getting sorted out now."
It was only later at Sunderland Royal Infirmary where he was being treated that police told him that four people had died.
Dr Nigel Stout checked Mr Davis's blood for whooping cough after hearing that his teenage son had also passed out during a coughing fit. The test revealed an infection had been present. In a rare condition known as cough syncope, coughing can lower blood pressure, leading to unconsciousness.
Mr Reed, Destiny and her mother would have died almost instantly, Durham coroner Andrew Tweddle was told. Mrs Reed, from Houghton-le-Spring, died later in hospital from multiple injuries.
Mr Tweddle returned four verdicts of accidental death.
After the hearing, Julie Duggan, whose son Sean was Natalie's partner and Destiny's father, said: "I don't know how he can live with himself."