Complex sentence: Remarkably, only two men were killed, when two shells smashed into the fort's southwest bastion, despite a deadly rain of some 2,000 mortar shells that the British bombardment fleet fired at the fort.
Split into simpler sentences: Remarkably, only two men were killed, when two shells smashed into the fort's southwest bastion. This despite a deadly rain of some 2,000 mortar shells that the British bombardment fleet had fired at the fort.