A judge drowned as his wife attempted to drive them through a heavily flooded ford while following directions provided by a satnav, an inquest heard.
Judge Jonathan Gammon was trapped in the car after it was swept 100 metres downstream. His wife, Priscilla Turner, managed to scramble to safety and told a woman who helped her: "I've killed my husband."
Turner told the inquest in Alton, Hampshire, that she was driving Gammon, 52, from Teddington, south-west London, to a secure hospital where he was to hear the case of a man detained under the Mental Health Act.
She was following a satnav that led her through the swollen ford at Headley in Hampshire.
Turner said: "I remember driving into the water. It just looked quite shallow. The next thing I recall was water coming into the car.
"I recall Jonathan trying his window and it wouldn't open, he tried the door and it wouldn't open. I recall him calling the emergency services and he was getting quite frightened.
"I remember saying to him: 'Stop panicking, I will sort things,' and I had a belief I would get us out of danger. The next thing I recall is standing on the bank and looking down on the submerged car.
"I remember getting into the ambulance as I asked if Jonathan was OK and I remember them saying: 'They are working on him now.'"
Dorothea Ryan came upon the submerged Toyota Yaris as she walked her dog. Turner was standing in the river and water was "rippling" over the roof of the vehicle.
Ryan waded into the water to assist Turner. She said: "Priscilla grabbed my hand. She was in an awful state. She was saying: 'Oh my God, my husband … what happened, please tell me it's a dream.' I said: 'No, it's a nightmare.' We just held each other. She was crying, I was comforting her.
"She was in total shock. She said: 'I've killed my husband,' I said: 'No, it was an accident.'"
Another local resident, Peter Hemmings, said that drivers frequently got into difficulties at the ford having followed satnav directions. He said: "We have to warn people visiting us not to use the road."
The inquest heard how the retained firefighter Jack Bancroft tried to save Gammon by climbing on to the car roof using a ladder and smashing the car windows. He managed to get to Gammon and released him.
Recording a verdict of accidental death, the North Hampshire coroner Andrew Bradley said he had personally inspected the warning signs in place at the ford following the incident in April and said they appeared adequate.
He said he would not be making any recommendations as the use of the ford was under review by Hampshire county council.