The invasion force had no artillery and was completely annihilated.

dismembered : (of a body) having had the limbs cut off.
reduced : make smaller or less in amount, degree, or size.
destroyed : end the existence of (something) by damaging or attacking it.
split :break or cause to break forcibly into parts, especially into halves or along the grain.
annihilated : destroy utterly.


Synonym of annihilated is destroyed