The answer is: Burned his house down while still inside it

1 Ki 16:18

King Zimri’s tragic end offers a distressing glimpse into a chaotic period in Israel’s history. Reigning for a mere seven days, Zimri’s rule was a whirlwind of treachery and violence. Following the assassination of King Elah and seizing power, Zimri realized he presented a target for retribution—particularly from Omri, a military commander who would eventually outmaneuver him. With his capture imminent, Zimri set fire to his palace, willingly becoming his own executioner. This act is a poignant reminder of how power can devour those who seek it through despicable means.

Interestingly, Zimri's demise highlights the themes of desperation tautly woven through the narratives of Kings. It's akin to a sudden storm sweeping across a calm sea—remarkably quick, utterly destructive, and bringing in the turmoil of change. The dramatic end echoes those of other notable figures in the Bible who met horrific fates, marquee examples being Saul and Judas Iscariot, splitting the shroud of despair and self-infliction.

Interestingly, the actual control of Israel quickly shifted to Omri after Zimri's self-destruction, cementing the turbulent political needle of the time. It’s like a game of chess where the betrayal of a few pawns leads to a compelling fight for a tundra of thrones. Through Zimri’s desperate action, we see a narrative flow that continues throughout history, echoing the struggle against power that burns hot, often consuming not just the diverse lives involved, but oneself as well.