A mother-of-three said her family is "broken" after a coroner ruled her parents were killed by carbon monoxide poisoning while on a family holiday in Egypt.
John Cooper, 69, and his wife, Susan, 63, from Burnley, Lancashire, had been enjoying a "brilliant" holiday while staying at the Steigenberger Aqua Magic Hotel in the Red Sea resort of Hurghada, the inquest into their deaths heard.
The couple were poisoned as they slept after the room next door to them was sprayed with pesticide and chemicals to kill a bed bug infestation.
Kelly Ormerod, the Coopers' daughter, who described her parents as fit and healthy for their age, had been on holiday with them, their three grandchildren and family friends.
After the three-day inquest hearing Ms Ormerod read a statement from the family outside the coroner's court.
"Our family still struggle to comprehend what we went through that day and feel like it should never have happened. The last few years have been the most traumatic time for all of us.
"Having to relive everything at the inquest has been harrowing but it was something we had to do for mum and dad.
"Our family is broken without them."
At around lunchtime on the eighth day into their holiday, the room next door to the Coopers, which had an adjoining door which was kept locked, was fumigated with pesticide, known as Lambda, for a bed bug infestation.
The pesticide was diluted with dichloromethane, a chemical that creates carbon monoxide, the inquest heard.
The room was then sealed with masking tape around the door, the inquest heard.
Hours later the couple returned to their room next door for the night. Their granddaughter Molly, 12, who was staying on a single bed in the couple's room, began to feel ill, and in the early hours Mr Cooper escorted her to the room of Ms Ormerod, her mother.
The following morning Ms Ormerod went knocking after her parents failed to come down to breakfast.
She found both her father, a builder, and mother, a cashier in a Thomas Cook bureau de change, seriously ill. Her father was declared dead in the room and her mother hours later in hospital.
Dr James Adeley, senior coroner for Lancashire sitting at Preston Coroner's Court, ruled that the deaths on August 21 2018 were caused by the spraying of the pesticide containing the chemical, dichloromethane, in the adjoining room and the couple then inhaling the vapour resulting in their deaths from carbon monoxide poisoning.
He said the spraying had created sufficient vapour to pass under the adjoining door and poison the couple.
Earlier, the three-day inquest heard from toxicology expert Professor Robert Chilcott.
He told the hearing in less developed countries the pesticide Lambda is sometimes diluted with the substance, dichloromethane, which causes the body to metabolise or ingest carbon monoxide.
The hearing also heard from Home Office pathologist Dr Charles Wilson, who told the hearing the Coopers' hotel room had not been secured and it would be "inconceivable" such measures would not be taken in the event of a double death in a hotel in the UK.
The inquest, five years after the deaths, also heard of multiple, repeated attempts to obtain more documents and information from the authorities in Egypt despite numerous requests from the Foreign Office.
Coroner Dr Adeley said Mr Cooper's illness and death was rapid, but described the medical treatment provided for Mrs Cooper as "utterly insufficient" after she was taken to a clinic in the hotel before an ambulance was called, creating a delay of four hours before she got to hospital.
Jatinder Paul, a lawyer from Irwin Mitchell, representing the family, added: "To find out that the couple died from a pesticide that had been sprayed in an adjoining room, leading to carbon monoxide poisoning, is shocking and deeply concerning.
"It's now vital that lessons are learned to ensure a tragedy like this doesn't happen to future holidaymakers."