Police investigating a house fire in Derby which killed six children have said it was probably started deliberately.
The announcement comes on the same day that the latest victim - 13-year-old Duwayne Philpott - died in hospital.
Derbyshire Police's Assistant Chief Constable Steve Cotterill said: "The initial indications are that it was deliberately set. Forensic investigations are continuing.
"It's early days, I'm sure you will appreciate that the examination of that scene has taken some time.
"What we need to do now is to get the results back from the forensic examination of articles that we've seized."
Specialist investigators, including fingerprints officers and sniffer dogs, have been examining the scene.
Duwayne had been in a critical condition in Birmingham Children's Hospital since Friday morning when the fire swept through the family home in Allenton, Derby.
His parents were at his bedside when he died overnight on Monday.
Duwayne's brothers and sisters - Jade Philpott, 10, John, nine, Jack, seven, Jessie, six and five-year-old Jaydon - all died in the blaze.
The Philpott family on Sunday agreed to turn off the life-support machine for Duwayne, police said.
Assistant Chief Constable Cotterill said: "I am sad to confirm the news that Duwayne has died as a result of the injuries he suffered in the fire.
"My deepest sympathies go out to Mr and Mrs Philpott at this distressing time.
"The family has asked for privacy as they come to terms with the events of Friday and the loss of their children."
A spokesman from Birmingham Children's Hospital said: "Despite the intensive care team's greatest efforts, the injuries that Duwayne received in the fire were too great for him to survive.
"Our thoughts are with his family at this difficult time."
A 38-year-old man and a 28-year-old woman who had been arrested on suspicion of murder following the fatal fire were released without charge on Saturday.
The children were asleep in their beds upstairs when the fire broke out.
Their father, Mick Philpott, was downstairs at the time, and tried to get through the smoke and flames to save them.
Mr Philpott is said to have fathered 17 children and hit national headlines several years ago when he demanded a larger house to share with his wife Mairead, girlfriend Lisa and their children.
People from the estate say they have set up a charity called Catch Me When I Fall to help the family pay funeral costs and cover other expenses they may now face.