"Mind the Gap" - three little words that most Londoners barely notice anymore.
But for Margaret McCollum that simple instruction on the underground has a very personal meaning. It was the voice of her late husband Oswald Lawrence.
Robyn Dwyer explains:
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A lamp in the tower which houses Big Ben is to be switched off for the first time in more than 70 years.
Sir Bruce entertained audiences for more than seven decades.
Work in the tower will also pause over the bank holiday weekend.