An explosion that killed a toddler in Heysham, Lancashire, was caused by a cut gas pipe inside a property, police have said.
Police said they had launched a criminal investigation into how the pipe came to be cut in number 20 Mallowdale Avenue, with inquiries still ongoing.
George Arthur Hinds, who was aged two years and 10 months, died in the blast on Sunday 16 May.
His parents Vicky Studholme and Stephen Hinds were wounded, but not seriously.
And a 44-year-old man and 50-year-old woman remain in hospital with critical injuries.
Detective Chief Inspector Jane Webb said: “My thoughts first and foremost remain with George’s family and loved ones at this time, as well as those others affected by this incident.
“An incredible amount of work has been done at the scene in a relatively short space of time.
“And as well as identifying the source of the explosion we have also managed to recover some items of George’s, which I know means a lot to his parents.
“Our focus now is on trying to establish how and why the pipe inside number 20 came to be cut and those inquiries are complex and lengthy.”
The detective appealed for anyone who may have information about what happened to contact police.
Last week, the Commons was told that toys and belongings were “strewn all over the street” in the aftermath of the explosion.
David Morris, Conservative MP for Morecambe and Lunesdale, described the “heartbreaking” scene and said he “wasn’t prepared” for what he saw.
He told MPs: “I was invited by the local council to look at the site – I have to tell you it was heartbreaking.
“What I saw I wasn’t prepared for. There were belongings strewn all over the street and toys and just debris everywhere. The whole community in that area were out, they were all in shock.”