<P> On 5 July 2007, a westbound Central line train struck a roll of fire - resistant material which was lying on the track between Mile End and Bethnal Green stations . The first three bogies of the train were derailed and the driver applied the emergency brake, stopping the train after 148m . There were no serious injuries caused by the derailment, but 20 passengers received medical treatment . All 520 passengers were evacuated from the train along the tunnel to Mile End station . The derailment also caused some damage to the first two carriages of the train, to the track and to one signal . </P> <P> The immediate cause of the incident was a roll of fire - resistant blanket, approximately 1.8 m long, lying across one rail . The blanket had been stored in a passage the previous night and weighted down, but the wind from passing trains had caused it to unfurl and fall onto the line . There were four causal factors and four contributory factors related to the incident . The underlying cause was the lack of a comprehensive risk analysis being performed to support the use of fire - resistant blankets . </P> <P> A plaque commemorating the 1943 disaster was erected on the station's south - eastern staircase, on which the deaths occurred, for the fiftieth anniversary in 1993 . It bears the coat of arms of the London Borough of Tower Hamlets, and records the event as the "worst civilian disaster of the Second World War". </P> <P> The "Stairway to Heaven Memorial Trust" was established in 2007 to create a more prominent public memorial to those who died in the disaster . The memorial was designed by local architects Harry Patticas and Jens Borstlemann of Arboreal Architecture . It was finally unveiled outside Bethnal Green Tube Station on Saturday, 16 December 2017, more than 74 years after the event . It takes the form of an open inverted stairway of 18 steps made of teak overhanging a concrete plinth, and is a full - sized replica of the stairway where the disaster occurred . The names of the dead are carved on the exterior and the top covering has 173 small holes allowing light through representing the dead . </P>

Green stair at the east end of the green line