What does 2 Chronicles 28:7 mean?

Zikri, a powerful warrior from Ephraim, killed Maaseiah, the king’s son, along with Azrikam, who was in charge of the palace, and Elkanah, the king’s second-in-command. 2 Chronicles 28:7 - Modern Text Bible

(Even the royal family and top officials weren’t spared in the chaos and violence.)