What is the worst purely negative RNG event in your opinion?

I once had the artisan troupe hold festivals on my world. An event fired off at random after several years that straight up destroyed one of my colonies. It actually removed it from the planet. This is straight up pure negative and it pissed me off so much I just reloaded. There was no counter-play here other than to just decide not to utilize festivals anymore which is what I do. Losing an entire colony beyond my control is very detrimental to how I enjoy the game.