When we say something is "knocked to pieces", we are suggesting that it has been completely destroyed or shattered. However, there are many other synonyms that can be used to convey this same meaning with slightly different connotations. Some options might include: broken apart, reduced to rubble, shattered to bits, demolished, disintegrated, pulverized, devastated, obliterated, or decimated. Using synonyms such as these can help to add variety and nuance to our writing and better capture the emotions and impact of a subject being destroyed or damaged beyond repair.