This happened because of all the sins Baasha and his son Elah had committed and had caused Israel to commit, provoking the LORD, the God of Israel, to anger with their worthless idols.
Here is, I. The ruin of the family of Baasha foretold. He was a man likely enough to have raised and established his family - active, politic, and daring; but he was an idolater, and this brought destruction upon his family. 1. God sent him warning of it before.
Commenting on 1 Kings 16:1-14
And Omri went up from Gibbethon, and all Israel with him,.... He, and the army under him, broke up the siege of that place, and marched to Tirzah; which, according, to Bunting (c) were thirty six miles distant from each other: and they besieged Tirzah; the royal city, in which Zimri was. (c) Travels, &c. p. 162.
For all the sins of Baasha - We see why it was that God permitted such judgments to fall on this family. Baasha was a grievous offender, and so also was his son Elah; and they caused the people to sin; and they provoked God to anger by their idolatries.