Police have removed three bodies from a house in which three children and a man died in an explosion.
Officers are then set to take a fourth body from the shattered three-bedroomed home in Cheddleton, Staffs.
Roderick Hine, 44, was killed along with Samantha Carter, 16, Patricia Carter, 10, and Marcus Carter, 7.
The children's mother was at work when the incident happened on Thursday night. A man has been arrested in connection with the matter.
Post-mortem examinations are expected to be carried out on Saturday.
The arrested man remains in custody and is expected to remain so overnight. Police say he is not the father of the three children.
Work is continuing on stabilising the building which is unsafe.
A police spokesman said five people lived at the address - a 35-year-old woman, her male partner and three of her four children.
Det Ch Insp Dave Garrett: "The scene is one of the most challenging ever encountered by Staffordshire Police.
"We have to ensure any evidence inside the building and from the surrounding scene is protected and gathered. This is a painstaking task which could take several days."
The blast happened in Hillside Road and developed into a severe fire.
Six houses surrounding the home were evacuated because of the blaze on Thursday night and part of the road remains sealed off.
CCTV pictures recorded from a neighbour's garden, obtained by the BBC, show the moment the explosion happened, followed by at least two other blasts.
Eye-witness Audrey Spooner said: "It was just an inferno, I've never seen anything like it."
Roy Spooner said: "There were flames coming out of the roof and there was fire balls coming out from above the windows."
Staffordshire ambulance service said it was first alerted by a call saying there were "sounds of some form of explosion from the property and screams".
Staffordshire fire service's Neil Backes said: "The rear of the property is very severely damaged as is the first floor and the fire has gone through the roof and made the first floor unsafe.
"It's a tragic situation. Our officers tend to rely heavily on their experience during these times.
"It's not something we're unaccustomed to, but it never ceases to surprise and shock us when these things happen."