Mr Vernon's two daughters, Theresa, 3, and Philippa, 7, and the daughter of a family friend, Sophie Beloe, died in August 1982 when the family Volvo driven by their nanny clipped a kerb, spun out of control and crashed into a river at Ynys Isaf, Powys.
Katherine Bosley, the nanny, escaped through a window but the three children drowned. Mr and Mrs Vernon were called to the scene by police and watched as the car was pulled from the river.
"From the bank they watched helplessly as hope came and went. There is no need to detail the horror of the event; it was every parent's nightmare become a reality," said Mr Justice Sedley.
The judge said Mr and Mrs Vernon arrived at the scene not knowing whether their children were alive or dead, as rescuers struggled with inadequate equipment to get to the car.
The couple and Ms Bosley, who was distraught and blaming herself, could see Theresa strapped in her seat. Movement of her leg in the water made it seem she was still alive but it then became clear that all three children had perished.
The accident destroyed Mr Vernon's marriage and left him a helpless and dependent shadow of his former self. Now 52, and living alone, the judge said he lived a chaotic life and was incapable of functioning as a normal human being. He lived surrounded bypiles of dirty dishes and laundry and chaotic paperwork.
In 1985, three years after the accident, Mr Vernon began proceedings for damages against Ms Bosley's insurance company, General Accident. His company making printed circuit-boards collapsed in 1986.
By February 1988, the dispute with the insurance company had narrowed to the level of compensation.
Mr Vernon's case was that the trauma of the accident had ruined what would have been a successful business. His counsel, David Blunt QC, claimed that the accident transformed him from a "quite outstanding, intelligent and capable" businessman to an unemployable shadow of his former self.
The insurers insisted that the accident had not changed him psychologically and that he "blamed everything and everybody but himself" for the failure of his company.
Mr Vernon was awarded £1m for loss of earnings, £152,000 for future medical care and general needs, and £37,500 for the injuries he received. Richard Bretton, Mr Vernon's solicitor, said it was the largest award for a post-traumatic stress disorder. Payment was stayed pending the judge's ruling on interest and costs. The insurers are considering an appeal.Reuse content