The Mount under fire: World War 2

As early as February 1937, the Post Office began to prepare for a new war. Staff were trained and prepared to take on extra duties so that there would be as little disruption to the mail as possible.

Structural alterations were made to the Post Office Underground Railway so it could be used as an air raid shelter for staff. An auxiliary bomb disposal unit was set up at the Mount, and its members earned high commendations from the commanding officer of the Royal Engineers for their many efforts during the war. The sorting office roof had been used since 1908 as a shooting range for the Post Office Rifle Club, but at the outbreak of war it was given over to more serious pursuits, as an air raid warning post was installed.

Air raids devastated a number of buildings in the London Postal Service and Mount Pleasant did not escape. The first major incident occurred on 16 October 1940 when a high-explosive bomb fell on the Farringdon Road entrance to the Parcel Block. The resulting crater caused a collapse in the road. Fissures ran across the whole of the East Yard right up to the wall of the building. This made the yard impassable and split the Farringdon Road water main, which flooded the Post Office Underground Railway tunnel beneath. 

On 18 June 1943 the Parcel Section was all but destroyed by a single incediary bomb. Exploding into the block towards the north east corner, the bomb caused a fierce fire which soon had the whole building ablaze. The fire was fought for four hours but almost the entire building was gutted, including 77,000 parcels. Two members of staff were killed and a further 34 were injured.