Nine vehicles were damaged in the crash in August, 2006
A lorry driver suffering from sleep apnoea admitted nodding off at the wheel and causing a pile-up which killed a man, an inquest has heard.
Toby Tweddell, 25, was killed when Colin Wrighton, 54, ploughed into a queue of stationary traffic on the M62 motorway in Merseyside.
A total of nine vehicles were damaged on August 8, 2006.
Mr Tweddell, from Sale, Greater Manchester, died of multiple injuries. A verdict will be recorded on 5 August.
Susan Allen, Merseyside Police's senior investigating officer into the crash, told the inquest: "There was no braking prior to this first collision. He failed to react to what was ahead of him."
She continued: "Mr Wrighton did drive in a way that fell far below what would be expected of a competent and careful driver."
Mr Wrighton told the inquest: "I was feeling all right then I started feeling faint and fuzzy.
"I started to feel a bit funny and I don't remember much after that."
He told the inquest he had been to see his doctor four months before the accident, complaining of tiredness.
The doctor did tests for diabetes, which came back negative, and it was not until after the crash that sleep apnoea was first considered.
The condition causes the upper airways to repeatedly close during sleep.
Sleeps with mask
Sufferers constantly wake up to breathe and are left tired the next day.
The inquest heard that Mr Wrighton now sleeps with a mask attached to a machine, providing him with oxygen throughout the night.
Several drivers gave evidence that the lorry crossed over into the hard shoulder, and then into the middle lane moments before the collision.
The paramedic who first treated Mr Wrighton told the inquest that he said to him: "What have I done?" and "How am I going to live with myself?"
Mr Wrighton was initially charged with causing death by dangerous driving, but the Crown Prosecution Service offered no evidence against him after his sleeping condition was revealed.
Merseyside Coroner Christopher Sumner adjourned the inquest to 5 August to consider his verdict.