Seven people were killed and 51 injured when a commuter train from Lithgow smashed into the back of the Indian Pacific on December 2, 1999.

A number of events will be held to commemorate the anniversary.

There will be a plaque unveiling specifically for survivors and victims’ families while the wider community have been invited to a picnic and formal dinner.

For Blackheath resident Krista Thomas — mother and grandmother of victims Natasha and Flynn — the commemorations will be “an opportunity to get together with people to share stories, to share laughter and even a bit of sadness if people want”.

A decade on and while the raw trauma of the day seems more remote, Krista said the pain caused by the absence of loved ones is something she will struggle with for the rest of her life.

For her, it has been about finding a way to adjust to life without Natasha and Flynn.

“Each person has a different way of coming to terms with the death of someone they absolutely loved and adored, and my way is to think of them constantly,” said Krista. “I have photos of them and I talk to my family and my friends about them, and they’re still very much a part of our lives. They’re not forgotten in any way.”

Krista’s son, Sean, is organising the December 2 dinner with his partner Cassie Heath. He said the aim was to not only commemorate those who died, but also to celebrate those who survived.

“We wanted to remember — as we will never forget — in a positive and meaningful way,” said Sean. “We wanted to do something a little bit special.”

Leura’s Everglades Garden will host the open community picnic on November 29. There will be music, speeches and a sausage sizzle while guests are also welcome to bring their own picnic lunch.

Blue Mountains mayor Adam Searle said it was fitting that the event be held in a “much-loved and peaceful location, where funeral services were held for some of those who lost their lives in the tragedy”.