A mother of three died after she was crushed by a mobile coffee shop van on the family driveway, an inquest heard.
But the hearing could not establish the exact circumstances that led to Tracy Evans, 41, becoming trapped by the Mercedes van at her home in Llandudno.
The inquest, held in Ruthin, heard the gradient of the driveway was only four degrees and the van had moved just a couple of yards.
Mrs Evans was taken to hospital but died from her injuries five days later.
In a statement read at the hearing on Thursday, her husband Jonathan Evans said they occasionally let the engine of the van run in winter to charge the battery.
It had been parked on their driveway on Roumania Crescent when, on 20 January, he asked his wife to switch off the ignition after about 30 minutes as he was going into town.
Later that afternoon, neighbours were alerted by children shouting "Mum, Mum", and they found Mrs Evans, who was a sales assistant at the town's Next store, pinned between the van and the wall.
Mr Evans said his wife would have just needed to reach inside the vehicle to switch off the ignition, adding: "There does not seem to be any sequence where she would have needed to release the parking brake."
A police investigation found the brakes would have passed an MOT test, but when the handbrake was applied by up to eight notches the van could still be moved with some force.
"The reality is that there is insufficient forensic evidence to form a view as to which way it came about," said coroner John Gittins.
Recording a conclusion of accidental death, he added: "The reason cannot be fully explained or determined but the vehicle moved and, very tragically, Mrs Evans became trapped."