“The king was angry.
He sent his troops.
ὁ δὲ βασιλεὺς ὠργίσθη, καὶ πέμψας τὰ στρατεύματα αὐτοῦ ἀπώλεσεν τοὺς φονεῖς ἐκείνους καὶ τὴν πόλιν αὐτῶν ἐνέπρησεν.
Well, yeah, the king was enraged and angry. First, he invited them to his son’s wedding feast. Then they would not come after two specific invitations. Finally, they mistreated and killed his own slaves. In the equivalent Luke parable, nobody died. But Matthew has a different story. Jesus said that he wanted revenge for the death of this king’s slaves. This king was very angry, provoked, and irritated (ὁ δὲ βασιλεὺς ὠργίσθη). He sent his army of troops (καὶ πέμψας τὰ στρατεύματα αὐτοῦ) to destroy those murderers (ἀπώλεσεν τοὺς φονεῖς ἐκείνους). Then he burned down their city (καὶ τὴν πόλιν αὐτῶν ἐνέπρησεν). This destruction of the city may have been a veiled reference to the fall of Jerusalem. Don’t mess with the king and his slaves!