Masonry found on Tube train roof after tunnel roof damaged
A lump of concrete has been found on the roof of a Central Line Tube train, the day after contractors drilled a hole through the tunnel roof.
Services were suspended between Marble Arch and White City during rush hour on Monday after masonry fell on the track.
Transport for London said the concrete had fallen on to the carriage during the drilling.
But the RMT union said this was "highly unlikely" and the rubble had fallen later.
The train had been in service for five hours before the concrete was discovered, and the union wants an investigation into whether loose masonry is still falling from the roof.
In a statement, TfL said: "We have investigated and have confirmed that the piece of concrete fell last night.
"We carried out a full safety review at the location last night before reopening the line to passengers and another this morning to check no further concrete had fallen from the tunnel."
'Not the first time'
Contractors were working on an extension to the Westfield shopping centre when loose concrete fell on to the westbound track below.
No damage was caused to trains or the track, but TfL carried out repairs before reopening the line.
Mick Cash, General Secretary of the RMT, said the damage "could easily have ended in tragedy".
"This incident of falling concrete from development works above the Central Line is not the first of its kind."
Peter McNaught, TfL's operations director, said it would carry out a "full investigation into the cause of this issue".