The Western Front:
In Flanders, British forces successfully take “Hill 60” – a small elevation (actually a spoil heap from earlier railway enginerring works, marked on maps with a 60m contour line) in a surrounding low-lying area – by tunnelling beneath the german defences and blowing the hill apart with explosives.
“the resulting explosions ripped the heart out of the hill over a period of some 10 seconds. It flung debris almost 300 feet into the air and scattered it for a further 300 yards in all directions… As the assaulting party closed on what was left of the German 172nd Regiment holding the hill, the dazed German’s screams could be heard over the din, as the British bayonets pierced them. Approximately 150 died, with only 20 being taken prisoner. Total British casualties were just seven.” [Firstworldwar.com].
The Dardanelles: The British submarine E-15 is destroyed by Turkish shells while trying to force the strait and enter the Sea of Marmara. [Burg & Purcell].