The account below of Olaf’s attack on London Bridge was based on Norse song. This incident is said to be the inspiration for the nursery rhyme “London Bridge is Falling Down”.
London Bridge is Pulled Down by King Olaf c.1014
So says [the scald] Ottar Svarte: “London Bridge is Broken Down. Gold is won and bright renown. Shields resounding, War-horns sounding, Hild is shouting in the din! Arrows singing, Mail-coats ringing – Odin makes our Olaf win!
From London: The Autobiography – 2,000 years of the capital’s history by those who saw it happen