A plaque bearing names of the Moorgate tube crash victims has been unveiled close to the station.
43 people died when a Northern Line train collided with the end of a tunnel in February 1975.
Nick Thatcher spoke to relatives of the victims about what the memorial means to them.
As a new memorial is unveiled in Finsbury Square to remember the victims of the 1975 Moorgate tube crash, writer Laurence Marks tells ITV London how the day took a tragic turn for him.
Mr Marks had been sent to cover the story for a national newspaper, only to discover that his own father was one of the victims.
He shares his story with our correspondent Nick Thatcher.
The new memorial has just been unveiled in a ceremony in Finsbury Square.
It honours the 43 victims of the Mootgate tube crash in February 1975.
Archive pictures from an ITV report on the Moorgate tube crash in February 1975 show the tragic extent of the incident.
Officers search through rubble-strewn carriages at the scene where 43 people lost their lives after the driver failed to stop at the station.
The exact cause of the driver's failure to stop the train was never determined. However, following the incident extra safety measures known as the "Moorgate protection" were introduced, which automatically stop a tube if the brakes are not applied.
A memorial honouring the victims will be unveiled in Finsbury Square this afternoon.
A memorial has been erected to honour those killed and injured in Britain's worst ever tube crash, nearly 40 years after the disaster.
43 people died and 73 were injured in the crash at Moorgate station on February 28, 1975. The memorial, in Finsbury Square, will be unveiled in a ceremony later today.
Campaigners raised £1,500 and Islington council made up the balance of the £6,000 cost.
A potential disaster on a railway line was averted today when two drills came through a tunnel wall on a busy commuter route.
Sasha Williams reports from King's Cross station.
The Hammersmith And City Line has been suspended between Moorgate and Barking due to a signal failure at Bromley By Bow - Inrix.