'I have no answers' - Three years on from a fatal gas explosion

"I've got so good at masking my agony," says Sana Ahmad, as she wears her daughter Sahara's name in a necklace

On a fine summer morning in the school holidays, a blast ripped through a quiet street in Thornton Heath, south London. The gas explosion on Galpin's Road on 8 August 2022 caused a house to collapse. A little girl, Sahara Salman, was found dead in the rubble.

Three years on her mother, Sana Ahmad, says she feels like she's still "reliving it daily", as she recalls the frantic search for her four-year-old daughter after "the whole house came down on me".

Hoardings adorned with toys and messages still surround the glaring gap in the row of terraced houses where she and her family once lived.

"Every time I go past the house, I'm re-traumatised," says Sana.

Several residents had reported a strong smell of gas in the days before the explosion. The Metropolitan Police began a criminal investigation in 2022.

But those who lost everything - and the wider community - say they are "frustrated" by the lack of detail and how long it is taking.

The gas explosion completely destroyed one home on Galpin's Road - three others have since been demolished

Sana laughs with tears in her eyes, remembering moments from her child's short life.

She recalls a day working from home during a Covid lockdown, when it all went quiet downstairs. She then found the kitchen full of "chocolate bubbles" - a result of Sahara and her brother mixing up a concoction of milkshake and washing-up liquid in the sink.

"I have the most incredible memories of them," she says, smiling sadly.

Sana shows no hint of anger or blame, but instead has a strong determination to keep going for Sahara's sister and two brothers. She speaks of the "profound grief" she has been processing in the last three years.

"My kids ask me some really difficult questions and I don't have the answers," she says.

Until the criminal investigation is concluded, Sana must wait for an inquest. Her daughter's death cannot even be registered.

"I think that no matter what the outcome is of this police investigation, as sad as it sounds, it's the reality of the situation: Sahara's not coming back. She's gone now. Sahara's gone now.

"I've come to the conclusion that the word 'justice' does not exist when loss is eternal. You only suffer an injustice."

Sahara Salman, who told her mum she had dreams of become a princess, was a month away from starting school when she died

Sana's house was next door to the one at the centre of the explosion on Galpin's Road, which belonged to Nigel Forde and Elaine McDonald. They spoke to me two years ago about the severe injuries Elaine sustained in the blast.

They have since settled into a new home in south-west London. Medical appointments are "weekly" now, rather than daily, as Elaine's mental and physical health slowly improves. However, she is "frustrated" that there have been no answers.

"Three years is a long time to have your life on hold. We need to know that somebody is responsible, and somebody is going to be held accountable for what happened to us, happened to Sana and her family - and the residents of Galpin's Road," Elaine says.

Both she and Sana have a dedicated police liaison officer and regular contact with the Met. But Elaine says she has been only "minimally informed".

'We really want answers'

Local people have contacted the BBC with concerns about the case and gas safety in general.

They told us that the gas provider, SGN, has recently been working on infrastructure in the area. One email said: "Those in the immediate area remain disturbed and really want answers."

They report that in the weeks running up to the explosion in 2022, there was a strong smell of gas - and the utility company was excavating the road.

The Metropolitan Police sent a local neighbourhood team to Galpin's Road on the third anniversary of the explosion and in recent days residents have received a letter updating local people on the investigation.

But we put it to the police that their recent statement was almost a carbon copy of the one sent to us two years ago.

We asked for more detail and they confirmed they were investigating "a case of corporate manslaughter and gross negligence manslaughter" and were reviewing "a significant volume of digital material".

The spokesperson said: "We have a dedicated team working on the investigation full time and we are working closely with Health and Safety Executive colleagues. As part of the investigation, we have begun early engagement with the Crown Prosecution Service, however, this remains at a very early stage."

They added the investigation was "exceptionally complicated and intricate in the level of detail required" so the force was not able to say when a conclusion could be expected.

Hoardings around the destroyed house are adorned with toys and messages

While she waits, Sana posts on social media channels with the hashtag Justice4Sahara, as a way of processing her trauma and campaigning for gas safety.

Along with raising her children, she says it is her job now to talk openly about grief, hoping it will help others.

"Sahara was such a loving, kind, gentle soul - that's what she would have wanted us to do to keep her memory alive".

If you have been affected by the issues in this story, help and information is available on the BBC Advice Line page.