In 1900 Heugh was completely reworked for two 6-inch Mk VII guns using the standard configuration of two emplacements with underground magazine between. The defences were further modified in 1907 when the Lighthouse gun was replaced with a 6inch Mk VII and the Cemetery Battery closed. Manned by the Territorial Force gunners of the Durham Royal Garrison Artillery, these were the three guns that were to see action in the Bombardment of Hartlepool on 16 December 1914. During the bombardment (at 08:10), the leading German battle cruiser fired a shell which struck aground less than 100 metres from the battery. This marked the first death in action of a soldier on British soil in World War I. A plaque commemorating the event is found on the coastal walkway just outside the battery.