Survivors of the Hatfield rail crash will join those bereaved by the tragedy to mark the 10th anniversary of the disaster today.
The four passengers killed when an express train derailed on October 17 2000 will be remembered in a service at St Etheldreda's Church in the Hertfordshire town.
Then, survivors and families of those who died will go to the scene of the accident near Hatfield station for another service which will start at 12.20pm.
This will include a period of silence at the exact moment of the crash - 12.23pm.
Both services will be conducted by the Rector of Hatfield, the Rev Richard Pyke, who comforted survivors and the bereaved after the crash.
The family of one of those killed - pilot Steve Arthur, 46, a father-of-two from Pease Pottage, West Sussex - are expected to attend the services.
Also due to attend the church service are railway staff, Mayor of Hatfield Linda Clark, other local councillors and the Archdeacon of Hertford, the Venerable Trevor Jones.
Mr Jones said: "I hope that the service will allow relatives and others a chance to know that their grief is not forgotten and also help them to receive comfort from the service.
"Those who lost their lives or whose lives were changed by the crash, as well as the rail staff who were deeply affected by the tragedy, are all in our prayers at present."
The church service will include the lighting of candles in memory of those killed. Hymns will include The Lord Is My Shepherd.
The crash involved a Great North Eastern Railway (GNER) express train from London to Leeds.
The train, travelling at more than 100mph, derailed after passing over a section of rail which then fractured.
Twelve GNER staff and 170 passengers were on the Intercity 225 service. As well as the deaths, there were 70 injuries - four of them serious.
A phenomenon known as gauge corner cracking, or rolling contact fatigue, was blamed for the crash.
Network Rail's predecessor company, Railtrack, introduced hundreds of speed restrictions on the railways while tracks were checked for cracking. Train punctuality times fell sharply for many months.
Official inquiries into the derailment showed that, north of the crash position, the rail had fractured into more than 300 pieces.
A Health and Safety Executive inquiry report said the train had passed over a section of track which was in a poor condition and which should have either have been replaced or a temporary speed restriction should have been brought in.
Railtrack and the maintenance company involved, Balfour Beatty, faced charges over the crash.
Manslaughter charges against the companies and also against six individuals were dropped but, in 2005, after an eight-month Old Bailey trial, Balfour Beatty was fined £10 million for breaching health and safety regulations.
Network Rail, which took over from Railtrack in 2002, was fined £3.5 million for also breaching health and safety regulations.
At the end of the trial, the judge, Mr Justice Mackay, said that, in his 30 years in the legal profession, he regarded Balfour Beatty's failure as the "worst example of sustained industrial negligence in a high-risk industry he had ever seen".
Rail Minister Theresa Villiers said: "The impact of the tragedy at Hatfield still resonates today and my thoughts are with the friends and relatives of those killed and injured as they mark the 10th anniversary.
"The rail industry is working hard to ensure that disasters like this don't happen again. Rail travel has never been safer than it is today, and the memories of those who lost their lives will see us continue to prioritise the safety of passengers as we expand and improve our network in the future."Reuse content