Erith, a National Trench Warfare Filling Factory, was constructed next to the larger Thames Munition Works in 1915. For a short time a mortar filling station was connected to Slade Green station by the 1½ mile “Trench Warfare Light Railway”. Miss Mary Edith Sheffield, identified only as a superintendent at the Thames Ammunition Works in the Crayford Marshes adjacent to Slade Green, was awarded MBE in King George V's 1918 Birthday Honours. Interwar Slade Green endured a national tragedy. En-masse explosions at a former Trench Warfare Filling Factory operated by Messrs. W.V. Gilbert, a contractor to the Disposal and Liquidation Commission, caused blinding flashes and the death of 13 workers on 19 February 1924. The W.V. Gilbert factory was near to or adjoining Thames Munition Works. The parliamentary debate that followed showed that the contract did not require a Fair Wages Clause, and was exempt from the provisions of the Explosives Act of 1875. A prominent mass grave at Northumberland Heath stands in memory of the victims. Development may have stagnated in the interwar years. Records show a Baptist Church was built on Elm road in the early 1930s, and Anti-Aircraft defences were constructed on the edge of Slade Green in the late 1930s. Variant spelling persisted as evidenced by Parliament recording "Slade Green" in 1924 and at least one chartered geographer recording "Slades Green" in 1933. Thames Munition Works Ltd. became part of the Vickers-Armstrongs conglomerate in 1927. Second World War Throughout Second World War the marshes were used for the 4.5-inch HAA Guns of the 6th Anti-Aircraft Division, corresponding with No. 11 Group RAF. The 4th Home Counties Brigade (Kent) formed from volunteers in the surrounding area in 1908, deployed overseas, and manned London's air defences at Slade Green in 1941. The disused command post and circular battery ramparts remain in the marshes between Slade Green and the former munition works. Slade Green was subject to a series of air raids, notably the night of 16 April 1941 when incendiary raids caused many fires and explosions capable of levelling the area; these threats were contained by the brave intervention of residents resulting in the award of three British Empire Medals and a George Medal. The Museum of London states that Howbury Manor House, pictured within the moated medieval walls, was bombed during an air raid and then demolished. RAF campaign diaries show Thames Ammunition Works was hit on