New time-lapse footage has been released showing the progress being made below the capital on Crossrail.
More than five and a half miles of underground tunnels have now been dug.
These pictures show the work that is being carried out at the sites of Finsbury Circus and the new Liverpool Street Station.
The first Crossrail trains are due to run in 2018.
More top news
George Michael died in December last year at the age of 53.
PC Keith Palmer, 48, stabbed by Khalid Masood while on duty in the grounds of the Palace of Westminster last Wednesday.
Those gathered on the bridge fell silent at 2.40pm - the time the first call was made to police exactly seven days ago.