Bishopsgate IRA bombing 'a turning point for London'
25 April 2013 Last updated at 15:39 BST
Twenty years ago Bishopsgate, in the heart of the City of London, was the scene of a devastating IRA bombing which killed one person and injured 44.
Nearby buildings were damaged by the shockwaves and experts now say the terror attack marked a turning point in how security is dealt with in the capital.
BBC London's Alice Bhandhukravi talks to former bomb disposal officer David Williams and security expert at the Royal United Services Institute Margaret Gilmore.