The grandparents of three young children who died in a house fire in Bridlington say they are "distraught" by what has happened.
Robert and Sharon Hudson said they did not know how they would cope after losing three-year-old Maddie, Anthony, five, and nine-year-old William.
Their daughter Samantha Hudson, 27, is seriously ill in hospital and unaware that her children have died.
Mr and Mrs Hudson said the children were their daughter's "pride and joy".
In a statement issued by Humberside Police, the couple said: "We are unbelievably distraught by what has happened. Heartbroken is an understatement. We have had our hearts broken three times and now our daughter is critically ill in hospital.
"We just do not know how we will cope, which one of our grandchildren to grieve for first. How do we carry on and move on from this, in order to help our daughter?"
They described Maddie as a "little bright spark" and an "absolute treasure", who had just started nursery.
Anthony, known as AJ, was said to be "motorbike and car mad", and had lots of friends at school.
Mr and Mrs Hudson said William was "very loveable" and was always wanting to learn. His favourite subjects were said to be dinosaurs and insects.
They added that their daughter and her children had moved to Clarence Avenue in Bridlington just over a year ago to be closer to them.
The last time they saw their grandchildren was at a family get-together on the day of the fire.
Fire crews and police were called to the cul-de-sac, which is a short walk from the beach, at 2358 GMT on Thursday.
Police said there was nothing to indicate the fire was deliberate.