AN 81-year-old driver was killed when his car veered across the carriageway into the path of another vehicle, an inquest has heard.
Frederick Stone, known affectionately as Fred, was behind the wheel of his Kia Picanto on March 18, 2012, when it collided with a Mitsubishi L200 pick-up on the A52 near Swineshead.
Mr Stone and his wife Beryl were returning to their home in Pode Hole, near Spalding after visiting friends in Tattershall Thorpe when the accident happened shortly after 4.30pm around 20 metres from the Bullen's Lane junction.
Witnesses said they saw the car move out from a line of traffic as if it was trying to overtake but without indicating or changing speed. In a statement from Mrs Stone, read at the inquest, she said she had been talking to her husband right up until the crash.
She said: "The accident was a complete shock and a surprise to me, I really don't know how it happened..
"I remember saying 'Fred, what are you doing?'"
A post mortem examination found no obvious reason why Mr Stone may have suffered a blackout or lapse of concentration and the cause of death was found to be as a result of multiple injuries to the chest, abdomen, pelvis and limbs.
Paul Robinson was the front seat passenger in the Mitsubishi, driven by his wife Claire, when the accident happened as they travelled back to their home in Mareham-on-the-Hill from a day out at Baytree.
He said: "I was just looking around across the field. Then suddenly there was a change in the car, I looked forward and saw this car come down our side of the road towards us.
"There was a severe impact, we seemed to spin round down the grass for ages and came to rest backwards into the drain."
Mr Robinson and the couple's two young children escaped with only minor injuries but his wife suffered bruising and problems with her hip for which she is waiting to see a specialist.
Crash investigator for Lincolnshire Police, PC Stuart Cook, said he had been unable to establish a reason for Mr Stone veering across the road but said it couldn't be ruled out that sunlight dazzle hadn't been a factor however he thought it unlikely as only one other witness had mentioned it.
Coroner for South Lincolnshire, Robert Forrest, recorded a verdict of accidental death, saying: "It's tragic. There's been a very thorough investigation. It's very clear that Mr Stone moved out of the traffic line of which he was travelling.
"There is no obvious reason why this happened. It is a mystery."
Mr Forrest also plans to write to student nurse Jessica Hammel, who was a passenger in one of the cars travelling behind Mr and Mrs Stone, and who helped out at the scene until the emergency services arrived.
He said: "I'm going to thank her for the professional way she acted at the scene and copy it to her educational supervisor."