1 Kings 16:11-15

And when he became king, as soon as he sat on his throne, he killed all the household of Baasha; he did not leave a single male alive, either of his relatives or of his friends.

So Zimri eliminated all the household of Baasha, in accordance with the word of the Lord which He spoke against Baasha through Jehu the prophet,

for all the sins of Baasha and the sins of his son Elah, which they committed and into which they misled Israel, provoking the Lord God of Israel to anger with their idols.

Now as for the rest of the acts of Elah and all that he did, are they not written in the Book of the Chronicles of the Kings of Israel?

In the twenty-seventh year of Asa king of Judah, Zimri reigned for seven days in Tirzah. Now the people were camped against Gibbethon, which belonged to the Philistines.