Survivors of the disaster at Harrow and Wealdstone station in north-west London, in which 112 people died, will be at the service at Holy Trinity Church in Wealdstone.

On the morning of 8 October 1952 a London-bound express train missed a yellow signal and ploughed into the back of a stationary local train, then a third train crashed into the wreckage.

A plaque in memory of the dead will be unveiled and all 112 names will be read out in front of survivors and representatives of the rail industry.

Nearly 350 people were injured

At the service will be Gilbert Powell, 64, who was just 14 when he broke off his journey to school to spend hours helping to rescue people from the wreckage.

He was a boy scout travelling on a bus to Willesden Technical College when he saw the extent of the crash and decided to help.

Mr Powell worked with a doctor and a nurse and was even lowered down by rope to see if anyone was alive within the wreckage.

He said: "I saw some pretty awful sights. I must have worked for hours and I've really no idea how many people I helped."

Parishioners killed

Another memorial service was held at Christ Church in Watford, on Sunday.

Many of those killed had been parishioners at the church who had boarded at Watford Junction.

A total of 108 passengers and four rail crew were killed and nearly 350 people injured.

The worst UK rail accident was in 1915 at Quintinshill, in Scotland, when a passenger train collided with a wooden train carrying troops.

Fire swept through the troop train and more than 200 people were killed.