1941 Old Palace School bombing

The Old Palace School Bombing on 20 April 1941 caused the largest single loss of life of firefighters in the history of the United Kingdom. The Old Palace School in the Poplar area of the Metropolitan Borough of Poplar was being used as an Auxiliary Fire Service sub-station during The Blitz of World War II. 34 firefighters, 21 of whom had been sent from Beckenham in southeast London to assist their colleagues in east London, were present in the station when it was hit by a parachute mine.

Source: Wikipedia — 1941 Old Palace School bombing (CC BY-SA 4.0)