This article needs additional citations for
. (March 2016)
The "Second Great Fire of London" is a name used at the time to refer to one of the most destructive air raids of
the Blitz, over the night of 29–30 December 1940. For over three hours from 6:15 pm
 over 24,000 high explosive bombs and 100,000
incendiary bombs were dropped.
 The raid and the subsequent fire destroyed many
Livery Halls and City churches and gutted the medieval Great Hall of the
The largest continuous area of Blitz destruction anywhere in Britain occurred on this night, stretching south from
Islington to the very edge of
St Paul's Churchyard. The area destroyed was greater than that of the
Great Fire of London in 1666, 274 years previously. The raid was timed to coincide with a particularly low tide on the
River Thames, which made water difficult to obtain for fire fighting. Over 1,500 fires were started across London, with many joining up to form three major conflagrations which in turn caused a
firestorm spreading the flames further and towards
St Paul's Cathedral.
Winston Churchill urged that the Cathedral be saved at all costs. It was saved only by the dedication of the London firemen who kept the fire that was raging in St Paul's Churchyard away from the Cathedral, and of the volunteer firewatchers of the St Paul's Watch who fought to put out the incendiaries or firebombs on its roof. The 200 members of the St Paul's Watch were mainly recruited from the
Royal Institute of British Architects who knew the vulnerabilities of the structure and where to target firefighting efforts.
More than 160 civilians died during that night, with many more dying of their injuries sustained in this raid in the days that followed; 14 firemen died fighting the fires and 250 were injured.
 Buildings completely destroyed in the fire storm included 19 churches, 31 guild halls and all of
Paternoster Row. Paternoster Row was the centre of the London publishing trade and an estimated 5 million books were lost in the fire.
A famous photograph,
St Paul's Survives, taken from the roof of the
Daily Mail building by Herbert Mason shows the dome of St Paul's Cathedral rising above clouds of black smoke. The photograph was cropped for publication, with the original showing many more destroyed buildings in the foreground.