After the king had heard what was written in the scroll of the Torah, he tore his clothes.
The tearing of clothes is the Biblical sign of mourning. The king mourned because of how far astray he and the people before him had strayed from HaShem because they ignored the Torah. First through neglect, then through ignorance Israel pursued their own way instead of godliness. A broken and contrite heart is like a treasure to the Most High, but we should never wallow in our sorrow. When we fall, we have to pause to get back up and keep moving forward praying for strength to endure.