The Brunner Mond chemical factory had been built in 1893 to manufacture caustic soda and soda crystals. However, declining demand for caustic soda meant that production ceased in 1912 and parts of the factory stood idle. Due to a crippling shell shortage following the onset of the First World War, the War Office chose to use the spare capacity at the Silvertown site to purify TNT for explosive shells.
The chief scientist at the factory described the purification process as “manifestly very dangerous” and the company bosses themselves tried to dissuade the government for going ahead with the plan. Despite these concerns, and the fact that the factory was situated in a highly populated area, the Silvertown plant began to produce TNT in September 1915 at a rate of approximately 9 long tons per day.
At 6.52pm on the evening of 19 January 1917, a fire that had broken out in another part of the factory reached the stores of TNT. Approximately 50 tonnes exploded, completely destroying the factory and many nearby buildings. The blast could be heard as far away as Sandringham in Norfolk while molten metal was strewn across several miles, some of which damaged a gasometer in Greenwich and caused a giant fireball as 200,000 cubic metres of gas caught fire.
Over 60,000 properties suffered some form of damage from the blast, but the loss of life was fortunately a lot lower than it could have been. The explosion took place in the early evening when there were not many people in the factory, and people had not yet gone to bed in the upstairs rooms of their homes that suffered the most damage.