Complex sentence: The Dutch suffered their one killed during the first attack by the Luftwaffe, and their two wounded during the bombing by the Luftwaffe, when two of the soldiers manning the anti-aircraft guns were hit.
Split into simpler sentences: The Dutch suffered their one killed during the first attack by the Luftwaffe, and their two wounded during the bombing by the Luftwaffe. Two of the soldiers manning the anti-aircraft guns were hit.