Lorraine Kelly is returning to Dunblane in a new documentary to speak to survivors and families, 25 years after the most lethal mass shooting on British soil.

What happened in the Dunblane massacre?

25 years ago, 16 children – aged just five and six – and teacher Gwen Mayor were murdered by gunman Thomas Hamilton when he opened fire on a gym class at Dunblane Primary School.

Hamilton, 43, then killed himself.

The massacre, which took place on March 13, 1996, in the Stirlingshire town, shocked the nation and led to the UK enforcing some of the strictest firearms legislation in the world.

The Herald: Gwen Mayor and her class at Dunblane Primary. Gwen Mayor and her class at Dunblane Primary.

Two new Firearms Acts were passed, which saw the end to private ownership of handguns in the UK.

Saturday marks the 25th anniversary of the massacre, but a quarter of a century on, the events of that day understandably still remain raw for the survivors and families of the victims.

Many children of Dunblane primary school still bear the physical and mental scars of the ordeal, although a number have chosen to move away from the town.

The most famous survivor of the massacre is tennis champion Andy Murray, who was a pupil at the school with his brother Jamie.

Andy had been walking to the gym when the shootings had begun, narrowly avoiding being caught up in the tragedy.

The Herald: Dunblane murders. 15/3/1996. Picture: Martin Shields Dunblane murders. 15/3/1996. Picture: Martin Shields

He has previously said the terrifying incident had affected him deeply, but hoped his triumphs on the tennis court had had a positive influence on the town.

His mother and former coach Judy said the Murrays knew Hamilton, a 43-year-old unemployed former shopkeeper, and had even given him lifts in their car.

She said she still found it difficult visiting the school and purposely avoided the gym where the shootings took place.

How can I watch Return to Dunblane with Lorraine Kelly?

The new documentary is presented by Lorraine Kelly and will air on STV at 9pm this Thursday.

Lorraine Kelly reported on the horror of that fateful day for GMTV, and will now return to speak to survivors and families.

She broke down in tears on TV in 2013 as she recalled seeing victim Joanna Ross, five, in her coffin.

Kelly said: “It never really does go away and (I think about it) any time I see a sign for Dunblane or whenever there is something in America, where as we know it happens far too often.

“That was the hardest thing I’ve ever had to do in my life and I don’t think there will be anything else like that. Going back, I was remembering a lot of things.

“I remember the press conference and journalists are pretty hard-bitten – they have to be just to survive – but I was seeing grown men in tears.

“I remember the quietness and nobody quite knowing how to absorb this and how to cope with it.

The Herald: Sixteen children and a teacher were murdered by a gunman who opened fire on a gym class at Dunblane Primary School on March 13 1996. Picture: Stefan Rousseau/PA Wire. Sixteen children and a teacher were murdered by a gunman who opened fire on a gym class at Dunblane Primary School on March 13 1996. Picture: Stefan Rousseau/PA Wire.

“It’s things like that you remember and it just makes you realise how lucky you are.”

Scottish band Glasvegas have written an original musical score for the documentary, which also highlights the enduring spirit and resilience of the Dunblane community, who came together to change UK gun-ownership laws as a result of the attack.

Some have even become activists for those advocating gun control in the United States, following an increasing number of school shootings across the country.

Tom Giles, ITV controller of current affairs, said the programme "aims to throw light on how the community at its heart somehow, quietly and resiliently, pulled together."